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The Venetian system of urban transport is always in a state of contradiction between the radical differences of the network to an equally radical separation of its functions: the network of viable water and the network of viable land. The first is almost exclusively reserved for transportation of people, as well as goods shipments and trash pickup. The second comprises the majority of land movement of people and all of the final distribution of the goods.
The prevailing component of water traffic regulates the commercial activity of the transportation of people and goods. This double infrastructure for transportation is universally recognized as the optimal way of looking at the separation of the flow of transportation and therefore, by definition, the quality of urban life. This is comparable to the situation of a modern city.2
Nevertheless, the system of urban water transportation in Venice has reached, over the past few years, a crisis point, where pressing issues have been brought to the forefront. In order to be successful, rigorous attention must be paid to the planning of traffic and other components, such as the constant flow of movement.
The structure of the transportation network
Observed from the point of view of transportation, the canals in Venice present the typical network of a historical center from the middle ages, characterized by the streets’ irregular trends and their sectional variability. The peculiarity consists in the fact that, instead of converging in numerous public squares, the network of canals flow the water away along an axial course.
The presence of the lagoon, which encircles the city with wide and deep navigation channels, acts as a system of travel around Venice. The wide section of the Grand Canal and some of the main inner city canals connect the two systems of the inner and outer city. It certainly has had some minor difficulties with adapting to modern motorized traffic, particularly regarding the old city of dry land: with the exception of some limited branches, the entire network is accessible by motorboat.
The most important traffic arteries within and surrounding Venice can be represented by two concentric rings (red rings in figure on left). The outer ring includes the Canale delle Fondamente Nuove, Colombola, Tronchetto, Giudecca, Bacino di S.Marco, and the Canale delle Navi. The inner ring is made up of the central part of the Grand Canal and the entirety of the Rio Nuovo.
The next level of arteries includes the Rio de Noal, Canale di Cannaregio, the northernmost and southernmost tails of the Grand Canal and the Scomenzera. These canals connect the inner ring with the outer ring (purple). These connecting canals coupled with the rings themselves account for the majority of traffic in Venice if for no other reason than they are frequented heavily by taxis and vaporetto. Public transportation boats from the ACTV (Azienda del Consorzio Trasporti Venezia) travel all of these canals as well, except the Rio de Noal.
Moving past those two main groups of passageways, there are two more types of arteries that play a vital role in the flow of traffic in Venice. These are the secondary arteries (blue in the side diagram) and the bypass canals (yellow). The secondary arteries include the Rio de S.Sebastian, Carmini, Briati, and Tre Ponti. connecting the Canale della Giudecca to the Rio Novo. The blue canals also include the two parallel canals in Dorsoduro that allow travel between the Canale della Giudecca and the Canal Grande (Rio de San Trovaso and de San Vio), and the two parallel canals that connect outer and inner ring across the borough of San Marco (Rio de S. Moisè and Rio de la Canonica, S.Zulian, de la Fava and Rio del Fontego dei Tedeschi). The list of secondary arteries is completed by two canals that connect inner and outer rings to the north and East, namely the Rio dei Santi Apostoli and the Rio de Santa Marina (which actually connects the inner ring to one of the bypass canals described below).
The final major elements of the water traffic network in Venice are canals that bypass parts of the network and create shortcuts (yellow) between two parts of the inner and outer rings. For instance, the Rio de San Polo and the connecting Rio Marin e Rio de San Zandegolà together create a “Y-shaped” bypass that cuts right through the heart of the inner ring inside the boroughs of S.Polo and Santa Croce. Similarly, the Rio de Santa Giustina and the Rio dei Greci and Sant’Antonin form an inverted Y that connects two parts of the outer ring in the Castello region, as does the Rio de l’Arsenale a little farther East.
Now go and consider the problems created by the indiscriminate use of motorized traffic, first the issue of moto ondoso. Canal waves created by passing boats have the power to damage buildings and surrounding structures and they occasionally do. Moreover, the circulation outline changes continuously, as a consequence of the immense program to excavate and reconstruct the canals headed by the Comune and by Insula, in order to shorten the unavailability of the entire water network. In order to resolve this problem, the Comune proposed a plan of simple city navigation and assembled to review the transportation laws, with the objective of a definitive reorganization of the water traffic circulation taking into account the periodic essential features of the network.
=The problem of water transport: the urban factor
The difficult work of adapting the historical network of the canals into an effective modern traffic model has already been mentioned. There are also problems of building degradation as a result of the moto ondoso. This problem, in general terms – the incompatibility of motorized traffic with the ambient quality– is characteristic of a contemporary urban system, the case in Venice is due specifically to two factors, the first, the urban development, the second, the modernization factor.
The first factor dates back to the age of the beginning of land connections with the mainland, the construction of a railroad between Mestre and Santa Lucia and the first translagoon bridge (1846).This becomes more obvious with the construction of the translagoon road and the beginning of automobiles in the Piazzale Roma in the 30’s. The final step is seen in the beginning of the 60’s with the introduction of the new island Nuova del Troncheto, with the consolidation of the western city as the only access point between the people and the goods, and with the interruption of the circumnavigation of the floating city.
These changes reduce the original radial articulation of access from the outside to the city, with one network of inner connections between the main poles of Rialto, San Marco and Arsenale, and involve a monoaxial rigidity, centralized on the Grand Canal and the pedestrians parallel, along which the traffic is concentrated.The ancient canals function across the entire city and the water network is connected with the lagoon, on whose articulation the city was structured on long ago.
There have been a lot of adaptations of the pedestrian network to the new city organizational system directed towards the translagoon bridge. Little or nothing is changed in the structure of the water network, too delicate to be touched for greater architectural value, that is unavoidable to safeguard, but is surely underrated in its function of transport. Instead, the penetration in the heart of the city of the systems of land transport was assumed. The last attempt of reorganizing the water network, in relation to the new system of Venice access, is the creation of the river Novo, contemporary to the realization of the automotive connection over the lagoon and Rome piazza, inaugurated in 1933, than it marks itself also as the last example of planning integrated of a system of transportation - infrastructures and means - even though limitedly to the collective transport of persons. It goes remembered that this participation was preceded from a wide project debate, that the proposal of digging of another new channel saw contrasted on the spread director of traffic, naming canal Piccollo4, from the river of the Tolentini to the confluence with the river of ca' Foscari, that however would have demanded remarkable efforts of demolition in the Malcanton zone. Subsequently, the plan of reorganization of 19395 was written up by an engineer. Eugene Miozzi introduced interesting proposals of reorders to the transportation network, attempting to result in the reduction of traffic in the Grand Canal and to the fast connection with the external canals: the rectification and the increase of the Noale River in connection with Fondamente Nove, the reopening of the river terà of Sant' Agnese in connection with the Giudecca canal, the reopening of the river of Sant' Anna under Gribaldi street connecting between the river basin of San Marco and the Navi canal, the opening of canals in the zone of the Rome piazza, beyond to other smaller participation, between which some intermittent canals can be seen. The last occasion is the topic of new infrastructures for the water network to unite them with the urban level.
After 1939, the proposals have been limited to single objectives. As an example, during ` the national Competition of ideas for the formulation of the Urban Development Plan of the Comune de Venezia', the topic of the adaptation of the Noale River was brought up, and also appeared two new topics related to the improvement of the lagoons waters . The first considerable intervention within the network of water transport was in the Galeazze River, which enabled passing across L’Arsenale thanks to the opening of a passage in the building screen to the North with an alternative creation of a new canal parallel to that of the Nuove Fondamente, but within L’Arsenale itself, south of the public dry docks. It was finally realized, even though it was limited to public passage, with the inauguration in the summer of 1967 of the new line “Circulare #5.” The second intervention previews the realization of a new canal between the River Novo and the Della Guidecca Canal driven by a preferential hypothesis, as it were, by means of motors or by means of paddles. After the presentation of the General Regulatory Plan adopted in 1959, the discussions resulted instead in the abandonment of all the suggestions for aquatic matter and living things which sprang from the contribution of ideas. A proposal was put forth for a city that does not want to alter itself too quickly and that it could mechanize, modernize and energize at a high technical level with the circulation of motor boats. It would create a new canal with the functional characteristics of the Grand Canal, without the limitations, which would run from Punta della Stazione to the present point quickly unloading in the Guidecca Canal that part of traffic whose destinations are Zattere, Sacca Fisola, Giudecca, San Marco and others, until Lido. This new canal represents one physical continuation of the Grand Canal and permits, therefore, circulation around St. Mark’s, the Grand Canal, Nuovo Canal, Canal of Giudecca. The entire structure of the traffic appears justified. The proposal did not find practical application and this function was used in the Scomenzera Canal which was gradually freed from harbor traffic. More recently, from 1972-1992, talks were resumed regarding cutting across the northerly ____ of L’Arsenale to shorten the perimeter route around the eastern part of the city. The first project in this area, which is probably the most interesting, was introduced in a detailed plan that proposed a sharp cut to the original walls of L’Arsenale, framing one of the existing dry docks. At the end, the preliminary project of a new general regulatory plan of Venice of 1992 provided a variation from the PRG to internally link the Darsena Nuovissima of L’Arsenale with the Galeazze Canal. The recent establishment of part of the Giracitta ACTV lines that complete the circumnavigation of L’Arsenale provided for stops at San Pietro di Castello and at the basins of L’Arsenale, which renders these proposals particularly current and certainly suitable to decrease the time of the route covered.
The Problem of Water Transport – the Technical Factor
The second factor, technical in nature, can be traced back to the 1960s, a period in which the natural equilibrium between the infrastructure and means of transport is shattered, resulting in the growth of motorization and the increase in the number and size of boats. The first signs of the incompatibility between motorized traffic and building structures go back to the introduction of the first motorized boats at the end of the 1800s, the public service vaporetti of the Grand Canal line. After the first vision of lagoon and river connections between towns (Venice-Lido belonged to the town of Malamocco, and in 1868 put into operation the first public service vaporetti, Venice-Chioggia, Venice-Cavarzera, Venice-Fusina, Venice-Cavazuccerina, Venice-San Dona di Piave), on June 1, 1881, the first urban vaporetto entered in the lagoon to work in the Grand Canal, by government grant. If June 12 was the first test run, by June 20, the Venice Gazette published a letter in which detractors of the initiative for the first time raised certain subjects: the danger of navigation in the Grand Canal, the consequences created by the moto ondoso brought upon by propellers.
Still famous are the protests from the gondoliers which eventually brought about the Strike of October 31, although the motive was essentially economic, for fear that the new competition in the public transport sector would dominate everything, for up until now, they were almost unopposed. For a long time, the vaporetti were among the few motorized facilities circulating the city, but the traffic problems started to worsen during the years between the two world wars. Going back to 1925, a town regulation provided iron limits for the motoscafi destined to travel the internal canals, that they could not have a motor with more strength than 16 horsepower if it was gas-powered and 6HP if it was electric, nor could they transport more than eight persons.
The explosion of private motor boats happened instead at the start of the 1960s, a period in which, according to the statistics of the times, the rowing/paddle boats were cut by half compared to before the war; the motorized freighters practically doubled; and the pleasure boats with outboard motors multiplied approximately twenty-fold. In that period of time, moreover, it became more and more apparent that state laws that governed general navigation were insufficient, both internal and maritime, and were inadequate to deal with and resolve the typical problems of urban traffic. It included all the problems of traffic on any mainland city with the added environmental impact upon building structures.
In 1963, the new town regulations regarding the traffic flow of both rowing/paddle boats and motorized propulsion boats in the Grand Canal and also in the internal city canals had been approved by the Town Council for the implementation of technical specifications in the navigation codes, which had been put forth 11 years before. The regulations were initiated to deal with problems of motorized navigation, even if limited by some technical peculiarities of each boat, and did not directly deal with the issue of moto ondoso, but were actually intended to safeguard the public peace and quiet. They prohibited motorized transport during night hours; enforced silencing equipment for the containment of noise within 85 decibels up to 7 meters; prohibited the use of intensely loud signaling systems.
It is unique that in the general compliance with the rules of traffic routes, there existed a double standard in the system of passage in the internal canals: the boats with paddles/oars had to stay clearly to the left side constrained from rowing to the Veneta; meanwhile, the motorized boats were expected to stay to the right side, with the resulting difficulty of maneuvering at a crossroad/junction in a narrow canal, in which case the motor boat had to move to the left. At any rate, the rules that contrasted with the general laws of navigation, forced one to stay instead to the center of the canal and not to the sides. This particular double standard was formally eliminated only in 1996, although the town regulation that was substituted had been in force for more than thirty years. In fact, it is actually practiced currently.
Nothing was said instead relative to the problem of the moto ondoso. It was dealt with directly in general binding terms with the introduction of differentiated speed limits based on the type of boat and service provided, from which emerged the order of public demand expressly relating to water traffic: group transport of people (public lines); individual transport of people (public, but not one of the lines); water taxi – (a service for the public and for different administrative tasks;) freight transport; and traffic for private or leisure use.
The problem in safeguarding Venice attracted dramatic attention of the world in 1966, when floods submerged the city and endangered its physical survival, subsequently, it could also be exposed in terms of water traffic. The State responded with a special law in1973 specifically targeting atmospheric pollution, the cause of the degradation/erosion of stone, and in respect to pollution, prescribed that all motor boats in the lagoon that would adhere to the antipollution laws for valid motorized conveyances within a two year deadline. The Government commissioned the enactment of laws concerning the strength of the mechanisms of propulsion and of the necessary requisites to limit the pollution that came from them, anticipating that to make necessary changes to boats to limit hazardous pollution they were allowed special input. An appropriate parliamentary commission was expected, but nevertheless was never established, and the commission remained substantially unfulfilled.
A Search for Solutions: Planning motorized traffic and technological interventions.
During the 1970s uncontrolled expansion of motorized water transport brought the City of Venice to the point where it had to deal directly with the traffic subject. The Communal Council on July 21, 1972 approved a document, Guidelines of the Administrative Council’s Plan on the topic of the structure of the land. The title, “Communication in the Historical Center”, reported the following glimpses: “Water traffic across the network of internal canals flows normally and reasonably, not (affected) much with the opening of the new aquatic routes through the adoption of a system of one-way travel, prohibiting the parking and favorite routes of particular classes of water transport vehicles that prevents the overload and allows accessibility to every part of the city to freight traffic.” After the initial experience of the introduction of the one-way system, borrowed from automobile traffic methods, it was given to a university work group to analyze the viability of the water network and to propose some solutions. The work group tackled the subject, believing in tangible adjustments in the water transport system and its routes and also in the possibility of using technical/scientific methodologies directly derived from the latter; keeping with the specifications with respect to the nature of the boats used, which had radically changing with respect to the period in which the network had originated.
On the contrary, in comparison with comparable land situations, the absence of private motorization gained recognition with a positive perspective on water traffic, because it was just a small number of boats compared to the number of automobiles circling in the city. It was acknowledged, though, that there was degradation to the building structures due to moto ondoso, a negative element in the distinction between water traffic versus automobile traffic, other things being equal, and in the problem of the inadequate network with respect to the question of mobility. The solutions proposed were typical of an urban traffic plan before. Therefore, for a short period, they aimed for the optimization of circulation and movement, considering the moto ondoso only as a liability that reduces the function of the canal involved. The specific case was explained this way, as a normal problem of circulation, but also with the understanding of the need for radical intervention, for a fairly long period of time, beginning with urban maintenance to the management of urban structures. Individual study places importance on the problem of freight transport and proposes the typical interventions adapted to the route circulations, the flow of traffic with a system of one-ways, adopting a movement pattern that at least lightens the load on the Grand Canal on the return route against penetration to the strained western bridge. Transit in the canals that are the most degraded is prohibited only to water taxis, classified as minor in social importance, which are intended for a wealthy tourist clientele. But it was only in the 1980s that mere generalized speed limits were ruled as insufficient to deal with and resolve the problem of moto ondoso in the urban canals. In the 1980s, the Government Commission was reactivated to impose limitations concerning the strength of the mechanisms of propulsion which had been addressed in the special law of 1973. But this time the parliamentary commission established and pointed out the necessity of dealing with all the types of pollution produced by motor boats, hydrofoil, gaseous, from sewage and noise, identifying, first, a solution of differentiated speed limits, and second, the specific characteristics of a single technical class of boat, surpassing the legacies instead of the classes of transport or services performed.
The planning of water traffic
The most recent innovative element is the knowledge of the necessity to control traffic circulation with technological instruments, and still more important is realizing this in relation to the historical centers of the mainland with automatic control of the automobiles, and access to the zones which limit traffic. Continuous monitoring by satellite systems of boat services to areas of public interest and the use of control by means of cameras or systems of identifications can enforce limits, encourage a great self-control of boat drivers, and thus improve the relationship between traffic and the city.
Personnel Transport
Given the structure of the city, from the 1800’s there has been a watery predicament between the people and the automobiles. Sometimes it is quicker to walk, in short distances. The structure of the canals has prevented the formation of a net of public transportation. Instead public transportation has evolved around the Grand Canal, and for over 50 years the short cuts were actually a lot quicker than the motorboats.
It is meaningful that until the introduction of the motorization of public transit, the water services were integrated with the pedestrian network through a system of ferries that crossed the Grand Canal according to the distances by land: during the second half of the 18th century, the Rialto bridge was the single stable connection between the two parts of the city. Connections existed but the service of long transport to cross the Grand Canal intensified substantially after the revolution to organize easier access to the city, to continue the construction of the railway connections and the station in the western part of Venice. Eventually boats were introduced and arrived with the departure and arrivals of trains29.
Then came the introduction of a service line, which is characterized by frequent stops on opposite sides of the river. This substantially reduced the number of ferries and gondolas required, but they still exist as an alternative to the mechanized transport. The currently existing ferries travel from the Ferrovia to the Punta della Dogana, and some make stops at important points ( Santa Sofia al mercat di Rialto, San Tomà sul tragitto piazzale Roma- San Marco) while still more than 10% of traffic uses the Vaportetti line along the Grand Canal.
The services of gondolas for hire, already inaccessible to the greater part of the population, experienced a remarkable reduction. The motorization of taxis resulted in profession transfers from gondoliers to taxi drivers, which until stabilized, put 400 people unemployed, a substantial amount of people.
The development of mechanized public transportation remained absent along the canals of Venice for a long time, the Vaportetti introduced to the Grand Canal were the only usable means of transportation. For over 50 years the line grew smaller, the trip from Piazza del Roma to the Lido remained the only inner service to the city: the second (Rialto – Piazza del Roma- Saint Marc’s Square- Lido) was inaugurated in the early 1930’s with the opening of the Rio Novo. Public transportation along the Grand Canal was essentially to cater to tourists. The external connection ring, connecting Roma and St. Marc’s, with the island of Murano and Giudeca, was finally introduced in the 1950’s. From that time on public transportation only increased, proving its usefulness and increasing the number of boats and stops. For many decades, as a result, there has been an increase in canals connecting with the Grand Canal other than the Rio Novo. Like the short cut across the handle of Venice to the Rialto, these were not really any shorter, and only seemed short due to an increase in boat speed.
The perceived insufficiency during the 1970’s led to the development of a a hypothesis of circular functionality, according to several schemes. It is assumed that a circular service along the Grand Canal, from Roma-Rialto-Novo, would eliminate the damage caused by the stop of the Rialto (as boats continued to evolve) which caused problems in the community30. There have been two more lines proposed to interlace in the River Novo that allow connection, that was nonexistent before, between the external zones of the city and the inner zones, replacing the external circular line31.
In reality, the degradation of the canals and buildings along the Rio Novo-Rio di ca’Foscari has cost the city greatly. The direct line between the Piazza Roma and St. Marc’s through the Rio Novo has been adandoned and now is run along the Scor-menzer and Giudeca, lengthening the time and distance, and the Grand Canal returned to be, after the 1950’s, the only useable means for the line.
The maximum speed of the Vaporetti needs to be reduced from 13 to 11 km/h. The need for fast axial connections is reason itself for the restructuring of the canals in the last decade, the reduction of transport within the inner canals has begin being rationalized with the expulsion of direct connections and reorganization of the circular services. In this case they have also introduced new stops, creating better routes between the inner and external zones of the city, in particular between the canals of the Giudecca and the Grand Canal, through the new island of Tranchetta.
The popularity of the transport caught up with the capacity of the landings and new methods of transportation were designed oriented towards greater capacity with newer propulsion devices for reduced environmental impacts. The progressive reduction of use of the city canals for public transport has taken forward steps, carried out with the motorboat taxi by now standardized with a maximum number of 20 people and therefore assailable, equipped with a powerful motor it could reach speeds higher that the 20 km/h limit, and a significantly reduced size to navigate the smaller canals of Venice which were previously inaccessible. At one time taxis only catered to the rich, giving rates far too high, then they eventually stabilized to about 200, and recently, by means of other factors (the increase of rates for non-residents, the saturation of the city’s public transportation, the stretching of the times and distances of the lines, the continuous movement of masses of tourists, the development of the airport etc.) the taxi service has become a service for everyone: the transport is therefore increasing, with the increasing hourly employment of motorboats that parallels the development of services, sometime amplified by drivers lacking proper licenses.
The idea of simulating the use of water taxies is still to this day insufficient for small canals. Residents, in recent times, have been quite aware of the limits of the inner canals, with the prohibition of nocturnal services, and the same Comone has come up with a prototype for a minitaxi that balances functionality with environmental awareness, thanks to reduced dimensions which allow it to travel down canals in which a normal taxi could not and it creates a low amount of moto ondoso.
In reality, the reduced speed from the River Novo to the Grand Canal, eliminates size of the motorboats, if not the number of vaporetti. The elevated element of incompatibility with the city is generally related to water taxis, because of their bad hydrodynamics at 5-7 km/h. The city’s public transport now seems to have reached a relatively stable point of big problems and few realistic perspectives of solutions to reduce impacts.
The Transport of Goods
Much like the transport of personnel, the organization of goods transport, essentially city distribution, is mostly oriented to the east32. Localization of the only structure on the part of the Colombuola canal, continuing the Grand Canal beyond the railway station, the large director of distribution of the city is at the end of the Grand Canal, also the presence of guides that reference the limits of earth-water situated on land ( Saint Giuliano – Canal Salso, Treporti) it is interesting that essentially all city canals go towards the North of the Grand Canal also utilizing the connections with the island north of Venice, mainly Murano.
In the specific case of goods transportation, the presence of lowered arch ways on bridges does not constitute a barrier, so long as the tide conditions cooperate. The problem of the city’s good distribution effect on water traffic emerged in the 1970’s after the first survey33, and is very evident in studies by the Comone of Venice from the 1980’s, during which it has been tested. 34
The last negative element of the infrastructure is the insufficient of usage of city canals for goods delivery. There is consistent congestion at the landings, is due to the scarce joints time of the distribution activity. In order to resolve the first problem, the infrastructure characteristic and the therefore typical “affrontiabile” of the Comune, is to come to the realization of a new center of “interscambio” at the “marittima” Station that, ultimately to the realization of stoccaggio warehouses today absent, to manage the goods distribution more efficiently. This renders competitive as well as the circular watery way that the city in alternative to the Grande Canal. For the second, instead, that it concerns the technical – economical organizations of transport, occupation essentially entrepreneur, and up to now preferred to take part itself on the effects rather than on the causes, with normal approach and relative obligation both for the maximum dimension (in particular wide and “stazze”) that for the construction materials, (prohibition if utilities of iron of new construction, obligation of the “effcaci” shockproof equipments), then for the power (with limits in defined course). For the third party, and in course the reorder of the river systems landings with recovery of the situation already makes ususable and the time separation of the conflict.
The exposed problem and the assumed cures for this problem are very difficult to identify, yet leads one to question the legal situation of the lagoon navigation system. The lagoon is not controlled by a single administration. The real problem resides in the Venetian Lagoon35 state properties.
There is not one common authority which controls the inner city canals and the canals of the Lagoon Islands. This is the problem. The Scomerzera Canal, as an example of this, is an essential canal that connects the Grand Canal with the Giudecca Canal. Since this canal is classified as a harbor canal, it is controlled by the Harbor Master’s Office. The River of Galeazze, which is an important canal linking the north of the Lagoonto the river basin of San Marco, is across from the Arsenal, and is subjected to the command of the Navy. The zones in the North of the City are under the Water Management.
With the growing urgency of this problem, the need to unify the navigation rules of the canals is extremely important, but difficult to accomplish. The different regimes, as it might be called, argue that different areas require different rules.
In the same prescribed power of Venice on its city water, the organization deputies have a voice in the marine rules and inner navigation of the canals.
Many years have passed without much being resolved regarding the laws which govern the canals. The Governo has recently decided37 that the Providence of Venice will be coordinating the navigating of the lagoons with specific regulations in understanding with all of the local components and with the ministry of navigation, the work of the public and the environment, other then with the department of the city.
The esteem of the equality evolution of the water traffic and time
The ultimate problem of water traffic in the venetian canal is attempting to determine where boats will get stuck in knots of the canals and deciding on a way to reduce problems associated with traffic congestion. As far as of the past water traffic goes, there is little trace that remains for the more available report and informal notes. In order to protest the insufficient impacts, in the city consequently the rivers and canals are entirely necessary, “rese” note the quantity of average traffic circulating daily on the San Polo river (the main artery intersection, second design), consistently 89 bunches of cargo transport, 294 boats and 309 gondolas that transport people, for a total of 692 boats, entirely considerably decided that approximately a fifth of all the intersection are complex interesting canals. The traffic found in the same point 5 years after (1986) was approximately 500 boats: you can derive that the traffic in the past was actually quite intense, at least in the smaller canals, although it was totally compatible with the atmosphere, thanks to the propulsion to “remi”.
The system of traffic changed drastically at the end of the 70s, so consequently came the alarm for the increase of motorized traffic: the first scientific campaign was undertaken from 1977-1978, followed by a second carried out in 1986-1987. Worthy of a note moreover, the survey campaign carried out by Worcester Polytechnic Institute with the help of the UNESCO – Murst the internal canal of Venice between 1992 and 1994, they began to organize the data in computers following one scientific method at a time.
These campaigns were moreover the ones carried out in various seasons for an entire week at a station40. Unfortunately, the lack of a defined standard method was not always consistent to the volume of traffic in different period, volume subject for more to various meanings, there were not enough points, which made it very difficult to compare and in relation to continually find the order of the network: the unique sense of the institution was temporary to the navigation of the also important, and can also carry local imbalances in the distribution of the traffic that is not always rendered faithfully the total variation of the time movements.
If you examine the motor traffic that transits the Grand Canal in the rotten sense, in an eleven hour duration, from 7am to 6pm, in periods equivalent medium data regarding the stations, in the years 1978, 1986, 1987 and 1996, for which it has conclusive data41, excluding the ACTV. In the three sections of the Station, from the Rialto Bridge to the Accademia Bridge, approximately 700 in 1978 to approximately 1200 boats in 1986 with in increment of 71% in eight years, corresponds to an annual rate of 7%, a successive year in 1987 shows that there were 1300 boats which passed (8% rate): Nine years later, in 1996, they found approximately 1450, which they believe will double in 18 years, which the increase will eventually slow down., which introduces an annual rate of 2%. Examining the Rialto Bridge, more positions all network, emerges the obvious variations of traffic in time: they give approximately 560 passages in 1978 to approximately 1250 in 1986-87 and then approximately 1700 in 1996. Of the individual motorized traffic in eighteen years there was more of an increase in the first decade (annual rate of 11%), in the second (3%).
Of the motorized traffic that comes to that comprehension of the ACTV passage, for to get the total motorized traffic in the Grand Canal to the Rialto Bridge, 300 transits in the eleven hours is a medium estimate. The total traffic around is 2000 boats, almost completely motorized.
Of the many boats that can be seen travelling daily through the canals in Venice, they fit nicely into 21 categories. The first two types are reserved for cargo boats, large and small, respectively. Similar to delivery trucks on the highway, these cargo boats travel the same routes over and over again delivering items throughout the city. The third type of boat that can be seen on any day, in almost any canal in Venice is the public taxi boat. Due to the extremely high level of tourism in Venice, taxis are kept permanently busy traveling back and forth between the airport and hotels. Their business is increased more so by the greatly slower pace of land travel throughout Venice. Not all travel through the canal network of Venice is public transportation, however. Privately owned personal boats can be seen as well. They are generally quite small in comparison, manned by one or two people, and have a tendency to travel more quickly than other larger boats. Unlike cars in a city, private transport is representative of a great minority. Even native Venetians opt to travel publicly instead of using their own boats to travel more often than not. And if they are not going to take a public ACTV boat, they are still more likely to walk.
The Impacts of Traffic on Venice
As the use of fossil fuels rapidly increases alongside the development of newer mechanical technologies, we are constantly putting our environment in the way of potential harm. The smog in Los Angeles and Mexico City are prime examples of such harmful environmental problems. The air, however, is not the only part of the environment being negatively affected by our carelessness. The environment is constantly being exposed to various other types of pollution. Steps need to be taken in order to mitigate these harmful effects and help protect the environment in which we live.
While Venice’s traffic paradigm is what makes it so unique and beautiful, it is the only place in the world whose method of transportation has the literal ability to destroy the city. The wake pollution caused by the abundant use of boats for transportation of goods, people, and resources is continually eroding the canal walls and chipping away at the foundations of the city causing it to sink.
In general, noise pollution has been shown to increase stress levels and blood pressure. Before motorboats took over as the leader in Venetian transport, there was little to no noise pollution resulting from boat traffic. Gondolas and rowboats contribute almost no noise whatsoever except for the occasional whistles, accordions, and singing gondoliers. Now that motorboats account for a large majority of traffic, the constant hum from passing engines can be heard at all times of the day. Boats such as taxis or small personal boats do not account for too much noise provided they are traveling within the posted speed limits and are not taking turns recklessly. This is where the problem lies.
It is interesting to note that one can accurately identify which boat is passing through an intersection by sound alone. Gondoliers always give a yell or a whistle as a sign that they are taking a turn and they wait for a response which would indicate another gondola is at the other end of their turn. Cargo boats and trash boats typically slow down drastically and often come to a full stop before taking their turns seeing as they are large boats and frequently require wide turns. A large contributor to noise pollution, though, is the manner in which many taxis and small personal boats take their turns. Unwilling to slow down, many drivers prefer instead to lay on their horns beginning from the start of the turn and they do not let off until they have completed the turn. What is worse is that occasionally there is another boat coming from the other direction that has no choice but to duplicate this response so the oncoming driver might be aware of its presence. The biggest issue with noise pollution is that it is a major annoyance which could be dramatically reduced if only intersection regulations were more strictly enforced.
Boat engines, in addition to creating noise, also introduce harmful chemicals into the water and air. Increased levels of hydrocarbons have been found in samples of wildlife in the Venetian lagoon. In addition to harming wildlife, the water is unclean for contact with humans. Besides depositing dangerous chemicals, boats also constantly churn the sediment on the bottom of the canals which is primarily composed of human waste. As a result, coming into contact with the water poses serious health concerns. It is an unlikely goal to clean up the canals so much that they may be swimmable, but it is certainly within reach to mitigate the pile on of pollution by cleaning up engine deposits in an effort to provide a sustainable ecosystem in the canals and in the lagoon.
More obvious though, are the effects on the aesthetics of the city. The poor water quality and color detracts from the natural beauty of the canal network. Nobody doubts for a moment that Venice is one of the most unique and beautiful cities in the world, but invariably, the color and aroma of the water is mentioned as something that leaves much to be desired.
Through research, the causes of these contaminants can be better understood such that it will be easier to control and eliminate their harmful effects. Organizations such as Forma Urbis and Coses have performed traffic counts to quantify Venetian boat traffic in an effort to construct a traffic model for the city. This model is intended to simulate traffic flow through the lagoon and inner canals of Venice with dynamic accuracy to account for potential closings and other variables. Knowing how and where boats travel makes it possible to gain a better understanding of the impacts of traffic on the environment in Venice.
Venetian traffic is significantly different from the traffic that most experience. Typically, car traffic during rush hour is due to the commute to and from work. However, in Venice, most traffic is due to public, personal, or goods transportation. 46% of traffic is made up of public taxi transportation. 36% is made up of goods shipments while the remaining 18% is comprised of private transportation. The leading contributor to Venetian traffic is the tourism industry. With 18 million tourists every year and growing, there has never been more stress put on the environment and Venice’s 150 canals.
With the advent of motorboats, the Venetian canals have become repositories for engine byproduct. The exhaust of boat engines bubbles through the water and leaves behind hydrocarbon emissions. Similar to car exhaust being released into the atmosphere, these emissions are a detriment to the environment.
The evolution of motorboats into the Venetian canals has led to an observable increase in the amount of noise. As the boats travel through Venice, different engines at different speeds will cause varying levels of noise. Before Venice adopted motorized boat traffic, such noise was nonexistent. Now, it is unavoidable. Undoubtedly, this new noise pollution issue is something that needs to be addressed sooner rather than later. While noise pollution seems to pale in comparison to water and wake pollution, its effects can be great. It is well documented that prolonged exposure to noise can negatively affect ones hearing to the point of hearing damage and loss. One of the less known effects of noise pollution is its effect on cardiovascular health. Exposure to moderately high levels of noise pollution during a single eight hour period, or typical work day, can cause a statistical rise in blood pressure due to a measureable increase in stress levels. Increasing vasoconstriction causes the rise in blood pressure, which is a main cause of coronary artery disease.
Measurements of noise levels produced by traveling boats were collected over a 16 hour period by ARPAV, the Agenzia Regionale Per la Prevenzione e Protezione del Veneto. The team monitored the Rio Novo over the course of the day with several microphones set up to record sound from different angles. Each observation was time-stamped such that the individual noises could closely be associated with the boat passing by at each moment. The overall goal was to determine how much noise was produced by each boat at varying speeds and angles.1
Large cargo boats were the first boat type monitored during the study. Approaching from a 25 degree angle at 5km/h, they produced 74 decibels. This volume increased marginally as speed increased, but shoots up noticeably to 84.1 decibels when making a turn. Small cargo boats follow a similar pattern, although they are significantly quieter. Travelling at 5km/h, these small merchant vessels create 68.8 decibels. In a separation from their larger cousins, these boats are actually noisier when traveling quickly straight than when making a turn. When traveling at 10km/h, twice the posted speed limit, small cargo boats output 74.2 decibels. When turning, they create only 73 decibels.2 Public transportation accounts for a significant amount of Venetian boat traffic, and as such, taxis are found everywhere. The most common taxi model outputs 73.8 decibels when traveling in a line at 5km/h. When turning, however, they output 79.3 decibels. In this way they resemble the large cargo boats, but the difference between turning and travelling straight for taxis is less significant. In fact, even when traveling at 10km/h there is only a difference of 3 decibels. 3
Less prevalent in the overall scheme of Venetian traffic are personal sport boats. They cannot be ignored, though. When traveling at 5km/h, these boats output 71.4 decibels, and when they are turning these boats output 78 decibels. In keeping with the trend of other boats, they too create more noise when travelling faster. 4 Of course, little can be said about noise pollution without traffic data to supplement the amount of noise outputted by each boat type. To this end, the noise pollution data collected by ARPAV was compared alongside boat traffic counts carried out by COSES over the 2006-2007 years. The quantity of boats by type counted at each station was multiplied against that particular boat type’s average volume output such that a total sum of volume per station was determined. Then, these sums by station were compared to construct a noise pollution index for the canals of Venice.
When boats move through an area, they first displace the water by pushing it away from the boat. Then, as they leave the same area, a gap in the water is left which is quickly filled in by gravity’s effect on the surrounding water. This disturbance creates a wake, which can be devastatingly erosive to nearby structures. In general, this is not a problem, because the energy can disperse in large bodies of water. In the canals, however, where the width and depth is severely limited, this poses much more of a problem when the energy from the wakes is transferred into the canal walls.
The erosion of the canal walls raises an immediate concern to the structures on and around them. There have been many instances of buildings collapsing due to their structures being eroded from beneath them. A study was done that proved a significant amount of canal sediment was an accumulation of building fragments which had fallen into the water. Not only is this a safety issue, but the city faces the danger of losing some of its historical beauty. Wake pollution is rapidly becoming an unavoidable issue. The repair of the walls is quite expensive, ranging anywhere from 100 to 3000 Euros.5 Compared to motorized boats, human powered boats create little to no wake. Intuitively, wake pollution has only been a problem since the use of motorboats has become more prominent. The speed at which boats travel has a direct impact on the amount of wake they produce. There has been research done demonstrating that a 90% reduction in wake pollution can be achieved if boats traveled at the posted speed limits.
In 2002, a group of WPI students measured moto ondoso over a seven week period in an attempt to quantify wake pollution by boat type. They did this by measuring wake period, wavelength, and amplitude, as well as average speed by type.
Large cargo boats with a small payload output 1.84, 5.40 and 13.39 kg-m at 5, 11 and 20kmph respectively. They were determined to travel at an average speed of 13.39kmph and therefore output an average moto ondoso of 7.05 kg-m. It indicates a clear and direct increase of moto ondoso with respect to speed. This is mirrored in related examples. For instance, a large cargo boat with a high payload outputs 0.62, 5.44, 10.34 kg-m at 5, 11 and 20kmph respectively. Travelling at an average speed of 10.06, these cargo boats output an average moto ondoso of 4.25kg-m. The disparity in average moto ondoso between payload sizes is caused by the differences in average speed.6
The average moto ondoso output by boat type was calculated in order to determine which canals were most affected. The greatest contributor to moto ondoso by and large is the small cargo boats due to their extremely high average speed. Therefore, the areas where small cargo boats were prevalent tended to have the highest moto ondoso.
It should be clear that increased moto ondoso is the direct result of increased speed. In the aforementioned study, it was determined that only 3% of boats actually abided by the posted speed limits. Intuitively, more boats respecting the speed limit would drastically cut down the average speed, and therefore reduce the total moto ondoso output.