Urbanistica
Tram and Light Rail Transit in modern urban mobility systems
R.Emili
ABSTRACT: Since 1960, in Rome as in all western world’s cities, begins the exponential growth of individual transport by car. The consequence of this phenomenon was a gradual cities transformation: road saturation, increasingly intolerable levels of air pollution and noise, migration of inhabitants from downtown to suburbs and exasperated car commuting. These changes have led to sort out these issues is mandatory to rethink mobility systems traditionally based on highways and subway lines, much expensive in terms of Life Cycle Cost compared to cheaper and innovative Light Rail systems. The paper considers the comparison of Life Cycle Cost between different public transport modes, highlighting more favorable economic terms for Light Rail systems compared to other modes for a range between 5,000 and 12,000phpdt. Combining tradition with innovation three innovative systems have set examples followed in many other cities around the world: Strasbourg Euro Tram, Dallas Light Rail Transit, Karlsruhe Tram-Train network.
1. INTRODUTION
Since 1960, in all western world’s cities, begins the exponential growth of individual transport by car.
As time passes, the increase in the individual motorization rate has caused a transformation of human habits and consequently changed the cities’ shapes and layout (see fig.1).
These changes have also affected urban mobility systems using extensive tram networks.
Even in Rome, since 1960s, cars began to invade the streets, causing the need to have more city areas used by cars. Therefore, major public works were focused on continuous expansion of highway systems. The Rome tram system, at the time very large, was considered an obstacle to movement and parking of cars. For this reasons it was considered necessary to eliminate the trams to the city’s streets. Throughout the years there has been a continuous global growth of cars. In fact, today, the rate of the growth cars has consistently outpaced that of human population.
In cities, this phenomenon has produced saturation of the available road surfaces, as well as increasingly intolerable levels of air pollution and noise (see fig.2).
Since 1960, in all western world’s cities, begins the exponential growth of individual transport by car.
As time passes, the increase in the individual motorization rate has caused a transformation of human habits and consequently changed the cities’ shapes and layout (see fig.1).
These changes have also affected urban mobility systems using extensive tram networks.
Even in Rome, since 1960s, cars began to invade the streets, causing the need to have more city areas used by cars. Therefore, major public works were focused on continuous expansion of highway systems. The Rome tram system, at the time very large, was considered an obstacle to movement and parking of cars. For this reasons it was considered necessary to eliminate the trams to the city’s streets. Throughout the years there has been a continuous global growth of cars. In fact, today, the rate of the growth cars has consistently outpaced that of human population.
In cities, this phenomenon has produced saturation of the available road surfaces, as well as increasingly intolerable levels of air pollution and noise (see fig.2).
Figure1. The shape changes of the cities as a result of the mass motorization phenomenon.
Figure2.Rome, air pollution damage on the marble surface of the monument named Pyramid of Caius Cestius: to the left before the restoration works carried out in 2015, to the right after works.
In Rome, this process has produced the following paradoxical situation:
-Based on the 2014 census, residents in Rome are 2,872,021 people, with an average population density of 2,230.9 inhabitants/km2;
-The cars owned by Rome's people are on average about 0.7 car/inhabitant, which corresponds to the presence in Rome of about 2millions of cars.;
-The area required for car parking is on average estimated at 12.35m2;
-As a result, the area occupied by cars owned by the average resident population on 1km2 was approximately 0.01945km2, which is equivalent to about 1.9% of urban area;
-In Rome the artificial surface extension used for road networks amounted to about 1.47% of the entire municipal artificial surface (Italian National Conference ASITA, year 2011);
-The confrontation between areas occupied by municipal roads (1.47%) and those occupied by cars of resident people (1.9%), derive the following paradoxical situation (see fig.3): the area required for resident people's cars is 29.25% larger than the road network usable for their movement.
From statistical data regarding the movements of population living outside the municipality of Rome, carried out by the statistical research institute (ISTAT 2014), it follows that on weekdays traffic from areas outside the municipality of Rome would be an average magnitude of about 320,000 cars/day. Clearly this situation is further worsening compared to that shown in fig.3.
The paradox explains the following circumstances:
1) Expansion of motorcycle transportation mode;
2) Block of city traffic in rainy days that force a greater use of cars and the diminished use of motorcycles.
This urban disorder causes a migration process of Italian resident population in Rome’s central areas towards more peripheral areas (see fig.4). Several problems arise from this migration process, as the exasperated car commuting and social decay in suburbs due to the absence of a valid public transport linkage to the city downtown.
These changes concern all western world cities. In order to sort out these issues it is necessary to rethink mobility systems not only being based on the use of expensive highways and subways, but also on cheaper solutions in terms of both construction and operational Life Cycle Costs(LCC).
-Based on the 2014 census, residents in Rome are 2,872,021 people, with an average population density of 2,230.9 inhabitants/km2;
-The cars owned by Rome's people are on average about 0.7 car/inhabitant, which corresponds to the presence in Rome of about 2millions of cars.;
-The area required for car parking is on average estimated at 12.35m2;
-As a result, the area occupied by cars owned by the average resident population on 1km2 was approximately 0.01945km2, which is equivalent to about 1.9% of urban area;
-In Rome the artificial surface extension used for road networks amounted to about 1.47% of the entire municipal artificial surface (Italian National Conference ASITA, year 2011);
-The confrontation between areas occupied by municipal roads (1.47%) and those occupied by cars of resident people (1.9%), derive the following paradoxical situation (see fig.3): the area required for resident people's cars is 29.25% larger than the road network usable for their movement.
From statistical data regarding the movements of population living outside the municipality of Rome, carried out by the statistical research institute (ISTAT 2014), it follows that on weekdays traffic from areas outside the municipality of Rome would be an average magnitude of about 320,000 cars/day. Clearly this situation is further worsening compared to that shown in fig.3.
The paradox explains the following circumstances:
1) Expansion of motorcycle transportation mode;
2) Block of city traffic in rainy days that force a greater use of cars and the diminished use of motorcycles.
This urban disorder causes a migration process of Italian resident population in Rome’s central areas towards more peripheral areas (see fig.4). Several problems arise from this migration process, as the exasperated car commuting and social decay in suburbs due to the absence of a valid public transport linkage to the city downtown.
These changes concern all western world cities. In order to sort out these issues it is necessary to rethink mobility systems not only being based on the use of expensive highways and subways, but also on cheaper solutions in terms of both construction and operational Life Cycle Costs(LCC).
Figure3.Rome, comparison between the area occupied by resident population’s cars (on the left) and the area made available from the Municipal road network for their circulation (to the right).
Figure4.Rome, change resident population in the municipality area between 1998 and 2007.
For these reasons, considerations must be made on the reintroduction of modern trams and on the utilization of existing secondary railways, constituting more economically sustainable mobility systems, especially for low-density residential areas.
In this regard it is especially significant all that was designed and built in the cities of Strasbourg Euro Tram, Dallas Light Rail Transit, Karlsruhe Tram-Train network.
2. LIFE CYCLE C0ST COMPARASION OF PUBLIC TRANSPORT SYSTEM
An important component of a transport system design activity is to define the capital need and its use program, so that they can meet different needs according to priorities. The Capital Project includes Life Cycle Cost analysis.
In the 90s, for the construction of a tram line in Rome (6km long), to cross the city central areas, Trastevere district, a Life Cycle Cost analysis was made on a thirty years’ technical lifespan, to compare the construction costs and maintenance/operating costs of a LRT (Light Rail Transit) mode with respect to those required for an BRT (Bus Rapid Transit) mode.
In this regard it is especially significant all that was designed and built in the cities of Strasbourg Euro Tram, Dallas Light Rail Transit, Karlsruhe Tram-Train network.
2. LIFE CYCLE C0ST COMPARASION OF PUBLIC TRANSPORT SYSTEM
An important component of a transport system design activity is to define the capital need and its use program, so that they can meet different needs according to priorities. The Capital Project includes Life Cycle Cost analysis.
In the 90s, for the construction of a tram line in Rome (6km long), to cross the city central areas, Trastevere district, a Life Cycle Cost analysis was made on a thirty years’ technical lifespan, to compare the construction costs and maintenance/operating costs of a LRT (Light Rail Transit) mode with respect to those required for an BRT (Bus Rapid Transit) mode.
Figure5.daily offer diagram of the passengers boarding per direction on the central tram line n° 8 in Rome (through the Trastevere district).
Figure6. LCC comparison between a modern tram line (light rail) and a BRT line (Bus Rapid Transit).
Fig.7. Light Rail: costs' incidence (5,000phpdt).
Figure8. BRT: costs’ incidence (5,000phpdt).
Figure9. Offering of 12,000phpdt, prices 2007. Results of the economic comparison of different transport modes in terms: LCC per seat.
The hypothetical calculations for an offer of a daily intake of passengers traveling in a single direction having a time pattern shown in fig.5, that during the daily service has little difference to the maximum peak (in this case between 7.30 am and 8.30 am).
The comparative Life Cycle Cost analysis on thirty years was repeated for different values of transportation capacity and for some possible economic cycles having different values of the inflation rate and interest rate on capital investment.
The figure 6 shows the LCC graphs (value Euro 1998, inflation rate index 3%, interest rate index on capital investment 5%), obtained by adding up costs for Capital Expenditure (CAPEX) and for Operational Expenditure (OPEX) of the two systems in comparison, in function of: Maximum phpdt (stands for Peak Hour Peak Direction Traffic: quantity of passengers boarding per direction during the peak hour) and Boarding passengers per direction/Day.
Figure 6 shows that for more than 2,500 phpdt (or beyond a daily offer of 30,000 passengers/day) the Rail Light mode is cheaper than the Bus Rapid Transit mode.
For 5.000phpdt, the different incidence for CAPEX and OPEX between the two projects in comparison is as follows (see figg.7,8):
-CAPEX Rail Light :41%;
-CAPEX Bus Rapid :15%.
-OPEX Rail Light: 59%;
-OPEX Bus Rapid:85%.
That comparison shows more initial expenditure required by the LRT system, that corresponds to a greater expense of a BRT system to be incurred during 30 years of operation. Comparative analysis can be extended, for higher transport performance, to other modes such as: Bus Rapid Transit, Light Rail Transit (at grade and elevated), Monorail and Metro.
For example, by applying the calculation method to a generic line having a 20km length and a peak demand of 12,000phpdt (levels of 12,000-15,000phpdt are generally considered the feasibility limits for a LRT system), in the hypothesis of an economic cycle
The comparative Life Cycle Cost analysis on thirty years was repeated for different values of transportation capacity and for some possible economic cycles having different values of the inflation rate and interest rate on capital investment.
The figure 6 shows the LCC graphs (value Euro 1998, inflation rate index 3%, interest rate index on capital investment 5%), obtained by adding up costs for Capital Expenditure (CAPEX) and for Operational Expenditure (OPEX) of the two systems in comparison, in function of: Maximum phpdt (stands for Peak Hour Peak Direction Traffic: quantity of passengers boarding per direction during the peak hour) and Boarding passengers per direction/Day.
Figure 6 shows that for more than 2,500 phpdt (or beyond a daily offer of 30,000 passengers/day) the Rail Light mode is cheaper than the Bus Rapid Transit mode.
For 5.000phpdt, the different incidence for CAPEX and OPEX between the two projects in comparison is as follows (see figg.7,8):
-CAPEX Rail Light :41%;
-CAPEX Bus Rapid :15%.
-OPEX Rail Light: 59%;
-OPEX Bus Rapid:85%.
That comparison shows more initial expenditure required by the LRT system, that corresponds to a greater expense of a BRT system to be incurred during 30 years of operation. Comparative analysis can be extended, for higher transport performance, to other modes such as: Bus Rapid Transit, Light Rail Transit (at grade and elevated), Monorail and Metro.
For example, by applying the calculation method to a generic line having a 20km length and a peak demand of 12,000phpdt (levels of 12,000-15,000phpdt are generally considered the feasibility limits for a LRT system), in the hypothesis of an economic cycle
The discussion on the system to choose was restricted between a system VAL (Véhicule Automatique Léger) and a modern tramway that could meet the Total Quality criteria, as summarized in fig. 10.
At the end the decision was made for a modern Tram, for the following reasons:
1) A capital expenditure (CAPEX) about four times lower than VAL system;
2) Minimization of the operational expenditure (OPEX);
3) The tram line can be easily associated with redevelopment and pedestrianization of some valuable areas, such as city central area (In this case Place Kebler and adjacent streets);
4) The access to trams is possible with simple platforms with a decking situated just 30cm from the rails.
5) Minimizing construction time and inconveniences caused to population.
As already mentioned, the Strasbourg’s tram project was developed according to the principles of the so-called Total Quality (see fig.10), which adheres to the following practical guidelines.
A) Maximizing of the positive qualities (exaltation of merits compared to competing modes)
A.1-Compared to Bus Rapid Transit mode, the bond constituted by the rails allows more length of the vehicles to increase transport capacity of each vehicle. In fact, the original EUROTRAM had 33m length and capacity 210 passengers (counted 4 pass/m2). The successive model has a length of 43m and the capacity of 288 passengers;
A.2-EUROTRAM has low floor and provides step-free boarding. It was designed to allow passengers in
wheelchairs, as well as those with strollers and bicycles, to embark and disembark more quickly and safely (see fig.11);
A.3-Each tram consists of intercom coaches to promote a better passenger distribution inside.
A.4- A tram design adapted to the needs of urban insertion and characterization of every specific city.
At the end the decision was made for a modern Tram, for the following reasons:
1) A capital expenditure (CAPEX) about four times lower than VAL system;
2) Minimization of the operational expenditure (OPEX);
3) The tram line can be easily associated with redevelopment and pedestrianization of some valuable areas, such as city central area (In this case Place Kebler and adjacent streets);
4) The access to trams is possible with simple platforms with a decking situated just 30cm from the rails.
5) Minimizing construction time and inconveniences caused to population.
As already mentioned, the Strasbourg’s tram project was developed according to the principles of the so-called Total Quality (see fig.10), which adheres to the following practical guidelines.
A) Maximizing of the positive qualities (exaltation of merits compared to competing modes)
A.1-Compared to Bus Rapid Transit mode, the bond constituted by the rails allows more length of the vehicles to increase transport capacity of each vehicle. In fact, the original EUROTRAM had 33m length and capacity 210 passengers (counted 4 pass/m2). The successive model has a length of 43m and the capacity of 288 passengers;
A.2-EUROTRAM has low floor and provides step-free boarding. It was designed to allow passengers in
wheelchairs, as well as those with strollers and bicycles, to embark and disembark more quickly and safely (see fig.11);
A.3-Each tram consists of intercom coaches to promote a better passenger distribution inside.
A.4- A tram design adapted to the needs of urban insertion and characterization of every specific city.
Figure10. Four principles inherent the Total Quality policy applied to the project of a modern tramway system.
Figure11.Eurotram vehicles at the Homme de Fer stop (photo, year 2012).
waiting times information, voice communication with users waiting at stops, etc.
B.3-To mitigate interference with road traffic and allow increasing commercial speeds, some streets have been devoted exclusively to trams. In correspondence of the road intersections have been installed special traffic lights for giving priority to the tramway passage. In addition, for elimination of any interference with existing structures on road surface, was built a line section in underground, with included a tram stop in correspondence with the main railway Station.
The first line section Strasbourg’s tram was inaugurated in 1994 (9.8 km length).
The success of this innovative project in terms of urban qualification, transport effectiveness and economic efficiency has been so impressive that it reintroduced the tram mode all over the world.
The Strasbourg’s tram system had been extended to a length of 42,7km and today it is constituted by six lines (about 54km in commercial operation).
For a network extension (11.8 km length) it was estimated an investment of €397.53millions (year 2008, source: Railway technology.com), which corresponds to an Index of the Cost Construction of Line about €33.7millions/km.
B.3-To mitigate interference with road traffic and allow increasing commercial speeds, some streets have been devoted exclusively to trams. In correspondence of the road intersections have been installed special traffic lights for giving priority to the tramway passage. In addition, for elimination of any interference with existing structures on road surface, was built a line section in underground, with included a tram stop in correspondence with the main railway Station.
The first line section Strasbourg’s tram was inaugurated in 1994 (9.8 km length).
The success of this innovative project in terms of urban qualification, transport effectiveness and economic efficiency has been so impressive that it reintroduced the tram mode all over the world.
The Strasbourg’s tram system had been extended to a length of 42,7km and today it is constituted by six lines (about 54km in commercial operation).
For a network extension (11.8 km length) it was estimated an investment of €397.53millions (year 2008, source: Railway technology.com), which corresponds to an Index of the Cost Construction of Line about €33.7millions/km.
B) Minimizing of the negative qualities (defects reduction compared to competing modes)
B.1-The main weakness of traditional tramways respect to bus mode, was the operating stiffness due to the impossibility of avoiding any obstacles located on the rails and, possibly, reverse travel direction to limit that service interruption only on the obstructed stretch. For these reasons EUROTRAM vehicles were equipped with driving cabs on both ends, so as to allow reverse travel on special railway switches arranged on line, avoiding the construction of bulky rings for march reversal of tram ride.
B.2- A weakness of the tramway mode is coming from the impossibility of overcoming any obstacle located on rails causing service interruption or delay of which users waiting at subsequent stops are unaware. To mitigate this situation on Strasbourg’s tramway, all systems commonly in use on metropolitan lines were introduced: centralized control system,
B.1-The main weakness of traditional tramways respect to bus mode, was the operating stiffness due to the impossibility of avoiding any obstacles located on the rails and, possibly, reverse travel direction to limit that service interruption only on the obstructed stretch. For these reasons EUROTRAM vehicles were equipped with driving cabs on both ends, so as to allow reverse travel on special railway switches arranged on line, avoiding the construction of bulky rings for march reversal of tram ride.
B.2- A weakness of the tramway mode is coming from the impossibility of overcoming any obstacle located on rails causing service interruption or delay of which users waiting at subsequent stops are unaware. To mitigate this situation on Strasbourg’s tramway, all systems commonly in use on metropolitan lines were introduced: centralized control system,
4. DALLAS LIGHT RAIL TRANSIT SYSTEM
Figure12. Dallas Central Business District and her very large residential area around.
Figure13.The radiating conformation of the LRT network deploys the transport service on most of the residential areas surrounding Dallas downtown.
Dallas is a typical American city (see figg.12,13), with its central nucleus that spread over a vertical dimension (Downtown or Central Business District) surrounded by a multitude of residential areas with very low population density (1000-1400 inhabitants/km2) connected to downtown with a large highways network, always saturated by cars traffic at rush hour.
An exasperated car commuting has arisen with expansion of residential areas all around Dallas’ central business district, which made it necessary to rethink the mobility system based on private cars.
These were motives why in the 90’s works were initiated for the construction of a public transport system on rails called LRT (Light Rail Transit).
The LRT system provides that rolling stock can travel on peripheral lines, or underground, with railway driving modes (driving assisted by an automatic signal system to allow speeds up to 110km/h) and, instead, in residential areas they can travel on the street, at grade, with tram driving modes (travel to sight).
The Dallas’ main road, Pacific Avenue, was closed to car traffic and devoted entirely to transit of the LRT vehicles (see figg.14,15). Here the rolling stock proceeds at grade with tramway driving mode. After Pacific Avenue the line through the rest of the city in tunnel, inside of which is also situated West End Station.
Originally every LRV (Light Rail Vehicle) was composed by two articulated coaches, equipped with a driving cab at each end.
The length of one LRV so composed was 28.24m, with capacity of about 200 people.
An exasperated car commuting has arisen with expansion of residential areas all around Dallas’ central business district, which made it necessary to rethink the mobility system based on private cars.
These were motives why in the 90’s works were initiated for the construction of a public transport system on rails called LRT (Light Rail Transit).
The LRT system provides that rolling stock can travel on peripheral lines, or underground, with railway driving modes (driving assisted by an automatic signal system to allow speeds up to 110km/h) and, instead, in residential areas they can travel on the street, at grade, with tram driving modes (travel to sight).
The Dallas’ main road, Pacific Avenue, was closed to car traffic and devoted entirely to transit of the LRT vehicles (see figg.14,15). Here the rolling stock proceeds at grade with tramway driving mode. After Pacific Avenue the line through the rest of the city in tunnel, inside of which is also situated West End Station.
Originally every LRV (Light Rail Vehicle) was composed by two articulated coaches, equipped with a driving cab at each end.
The length of one LRV so composed was 28.24m, with capacity of about 200 people.
The access to the vehicles load platform was located at a height of 100cm from the rails, therefore passengers access was through means of steps (a realization that at first showed a substantial American mistrust of low floor tram solution, similarly to what was done in Strasbourg). To allow access to disabled persons in wheelchairs and baby strollers, on the station were installed ramps or lifting mechanisms on a platform situated at the height of 100cm and conveniently positioned to allow driver’s assistance (see figures 15 and 16).
In 1996 the first stretch of 20 miles was inaugurated. Today, Dallas’s LRT system extends approximately for 145 km and carries an average of 103,100 passengers per weekday. For the great successful it was necessary to increase the vehicle’s capacity, creating a new Super Light Rail Vehicle (SLRV), by separating each LRV in two sections on their articulation joint and inserting an entirely new coach between them. Thereby rendering every SLRV a three-coach operational unit, having a capacity of about 250 passengers. So it was possible to constitute trains until four SLRVs, having overall length 150.57m and capacity of 1,000 passengers. The middle coach of every Super Light Rail Vehicle has a low floor to allow a direct access (no steps) to the passenger in wheelchairs, as well as those with strollers and bicycles (each SLRV middle section was also equipped
In 1996 the first stretch of 20 miles was inaugurated. Today, Dallas’s LRT system extends approximately for 145 km and carries an average of 103,100 passengers per weekday. For the great successful it was necessary to increase the vehicle’s capacity, creating a new Super Light Rail Vehicle (SLRV), by separating each LRV in two sections on their articulation joint and inserting an entirely new coach between them. Thereby rendering every SLRV a three-coach operational unit, having a capacity of about 250 passengers. So it was possible to constitute trains until four SLRVs, having overall length 150.57m and capacity of 1,000 passengers. The middle coach of every Super Light Rail Vehicle has a low floor to allow a direct access (no steps) to the passenger in wheelchairs, as well as those with strollers and bicycles (each SLRV middle section was also equipped
Figure14.Pacific Avenue. You can observe the abundant road signs prohibiting transit for cars (photo, year 2000).
Figure15.Pacific Avenue entirely dedicated to the new public transport system on rails. On left you can see the complicated system for lifting the disabled in wheelchairs to the level of the specific platform for their embarkation, located one meter above the rail (photo, year 2000).
Figure16.Underground stop West End. (photo, year 2000).
with a bicycle rack). By 2014 DART had converted all its No. 115 LRVs in SLRVs. Today, with the purchase of No. 48 new SLRVs, is operating a total of No. 163 SLRVs.
The figure 13 shows the radial configuration that was given to the network for extending the service to the widest areas possible. In correspondence of each peripheral station large interchange parking were constructed. The project was carried out over a period of 20 years and it would seem to have required a financial investment (CAPEX) limited to 1/3 of that needed for an equivalent conventional metro system.
The figure 13 shows the radial configuration that was given to the network for extending the service to the widest areas possible. In correspondence of each peripheral station large interchange parking were constructed. The project was carried out over a period of 20 years and it would seem to have required a financial investment (CAPEX) limited to 1/3 of that needed for an equivalent conventional metro system.
To meet the same requirements as described for Dallas, an original and innovative rail system called TRAM-TRAIN was adopted in Karlsruhe (Germany).
This system involves use of special rolling stock that can travel indifferently on railway lines and on tram lines (see figures 17 and 18).
To create a rail system of this type it is necessary to solve regulatory, technical and organizational issues.
The German guidelines for heavy railway operation (EBO) are different from German guidelines for tramway (BOStrab).
The traditional trams need modifications, to be able to operate in a DC power environment, as well as with AC power. Consequently, a dual-mode light rail vehicle was developed.
In 1992 the first Tram-Train line was inaugurated, from Karlsruhe to Bretten (see fig.18).
The Tram-Train vehicles operates between Karlsruhe (Marktplatz) and Grötzingen like a tram, respecting guideline BOStrab for tramway. In Grötzingen the Tram-Train vehicles change electric voltage (750VDC to 1,500VAC) and then operate as a heavy rail vehicle respecting EBO rail specifications on 18km tracks towards Bretten. In Grötzingen the train's accountability is transferred from AVG tram driver to the operation manager of Deutsche Bahn AG.
This goal was possible only through the co-operation and co-ordination between political Administrators of the cities interested, as well as Local Transport Companies VKB (Karlsruhe tram operator), AVG (tram-train operator), Regional Rail Transport Companies (DB Regio AG-Rhein Neckar Region, DB Regio AG- Baden-Württemberg Regionen) and All of these operators are coordinated by KVV (Transport Association of Greater Karlsruhe).
This system involves use of special rolling stock that can travel indifferently on railway lines and on tram lines (see figures 17 and 18).
To create a rail system of this type it is necessary to solve regulatory, technical and organizational issues.
The German guidelines for heavy railway operation (EBO) are different from German guidelines for tramway (BOStrab).
The traditional trams need modifications, to be able to operate in a DC power environment, as well as with AC power. Consequently, a dual-mode light rail vehicle was developed.
In 1992 the first Tram-Train line was inaugurated, from Karlsruhe to Bretten (see fig.18).
The Tram-Train vehicles operates between Karlsruhe (Marktplatz) and Grötzingen like a tram, respecting guideline BOStrab for tramway. In Grötzingen the Tram-Train vehicles change electric voltage (750VDC to 1,500VAC) and then operate as a heavy rail vehicle respecting EBO rail specifications on 18km tracks towards Bretten. In Grötzingen the train's accountability is transferred from AVG tram driver to the operation manager of Deutsche Bahn AG.
This goal was possible only through the co-operation and co-ordination between political Administrators of the cities interested, as well as Local Transport Companies VKB (Karlsruhe tram operator), AVG (tram-train operator), Regional Rail Transport Companies (DB Regio AG-Rhein Neckar Region, DB Regio AG- Baden-Württemberg Regionen) and All of these operators are coordinated by KVV (Transport Association of Greater Karlsruhe).
Figure17.Karlsruhe, Kaiserstraße. On the right is transiting a Tram operated by the municipal company VKB. On the left is transiting a vehicle TRAM-TRAIN operated by the specialist firm AVG (photo, year 2012).
Figure18.The first TRAM-TRAIN line from Karlsruhe to Bretten.
Figure19. Karlsruhe, Tram and Tram-Train networks.
Today, the Tram-Train network consists of more than 663km (see fig. 19) and, on basis the information provided by AVG, in the case of Karlsruhe-Pfinzta line, users grew from 4,000 passengers/day of the old traditional rail link to 25,000 passengers/day for the new Tram-Train link.
Today the Karlsruhe's Tram and Tram-Train networks carries 170millions passengers per year.
In Karlsruhe's downtown approximately 2km of tramway line run through Kaiserstrasse, the main shopping street mostly pedestrianized (see fig.17). On that street, traffic of tram-train vehicles and trams has become so intense to make it necessary to built a tunnel on the southern branch line, from Marktplatz to Augartenstrasse, to carry underground very of this traffic. The Stadtbahn tunnel has been under construction since 2010.
This transportation mode, using existing networks, requires a capital expenditure (CAPEX) virtually limited to purchasing only Tram-Train vehicles. Consequently, as Karlsruhe's experience shows, for the construction of Tram-Train systems, the main issue is not economical but rather of coordination and cooperation between Institutions and Operating Agencies at various levels, politicians, administrative, regulatory and operational.
6. CONCLUSIONS
At the conclusion of the above, it is the writer's opinion that combining tradition and innovation the modern Light Rail systems are technically and economically the most effective and efficient public transport systems for a range between 5,000 and 12,000phpdt.
These systems are optimal for the connection between the ancient city with the extensive low density housing areas that in time have grown all around.
The Systems brought into service in Strasbourg (Eurotram), Dallas (Light Rail Transit) and Karlsruhe (Tram-Train network) are good examples that drive the relaunch of the local public transport by rail all over the world.
Today the Karlsruhe's Tram and Tram-Train networks carries 170millions passengers per year.
In Karlsruhe's downtown approximately 2km of tramway line run through Kaiserstrasse, the main shopping street mostly pedestrianized (see fig.17). On that street, traffic of tram-train vehicles and trams has become so intense to make it necessary to built a tunnel on the southern branch line, from Marktplatz to Augartenstrasse, to carry underground very of this traffic. The Stadtbahn tunnel has been under construction since 2010.
This transportation mode, using existing networks, requires a capital expenditure (CAPEX) virtually limited to purchasing only Tram-Train vehicles. Consequently, as Karlsruhe's experience shows, for the construction of Tram-Train systems, the main issue is not economical but rather of coordination and cooperation between Institutions and Operating Agencies at various levels, politicians, administrative, regulatory and operational.
6. CONCLUSIONS
At the conclusion of the above, it is the writer's opinion that combining tradition and innovation the modern Light Rail systems are technically and economically the most effective and efficient public transport systems for a range between 5,000 and 12,000phpdt.
These systems are optimal for the connection between the ancient city with the extensive low density housing areas that in time have grown all around.
The Systems brought into service in Strasbourg (Eurotram), Dallas (Light Rail Transit) and Karlsruhe (Tram-Train network) are good examples that drive the relaunch of the local public transport by rail all over the world.
that expected an yearly increment of 9% for workforce cost and 5% for other costs (see References: 8th Urban Mobility India Conference & Expo). In this case, setting equal to the number 1.0 the value of a Light Rail Transit system (at grade), the calculation of each LCC per seat for every transport modes referred to above would lead to a costs ratio as shown in fig.9. In conclusion of the above, to the writer's opinion, it is possible draw the following considerations:
1) In high level demand corridors beyond 12,000phpdt, the Metro mode is the only feasible choice;
2) In corridors of medium level demand, between 12,000 and 5,000 phpdt, the Light Rail modes are perhaps the best choice;
3) Between 5,000 and 2,500 phpdt, the choice lies in two modes: Light Rail Transit and Bus Rapid Transit. More detailed analysis is needed;
4) In low demand level corridors, under 2,500phpdt, the choice lies on the BRT and Bus modes.
On average the Index Construction Cost per km (CAPEX/km), has the following quantity orders:
A) CAPEX Metro (undergraund): € 120-200 millions/Km;
B) CAPEX Light Rail Transit (at grade): € 30-60 millions/Km.
These economic considerations have helped to guide the choice of important cities towards public transport in Light Rail modes, considered more effective technically and economically more efficient, especially for residential low-density areas.
3. STRASBOURG (EUROTRAM)
Strasbourg has about 270,000 inhabitants. Also in Strasbourg, as in many cities of western world, trams were removed in 1960 to leave urban space for car traffic and parking needs.
After 30 years, In 1990, to solve the problems created by phenomenon Mass Motorization (increasing traffic and pollution) it was decided to build a new Public Rapid Transit system.
1) In high level demand corridors beyond 12,000phpdt, the Metro mode is the only feasible choice;
2) In corridors of medium level demand, between 12,000 and 5,000 phpdt, the Light Rail modes are perhaps the best choice;
3) Between 5,000 and 2,500 phpdt, the choice lies in two modes: Light Rail Transit and Bus Rapid Transit. More detailed analysis is needed;
4) In low demand level corridors, under 2,500phpdt, the choice lies on the BRT and Bus modes.
On average the Index Construction Cost per km (CAPEX/km), has the following quantity orders:
A) CAPEX Metro (undergraund): € 120-200 millions/Km;
B) CAPEX Light Rail Transit (at grade): € 30-60 millions/Km.
These economic considerations have helped to guide the choice of important cities towards public transport in Light Rail modes, considered more effective technically and economically more efficient, especially for residential low-density areas.
3. STRASBOURG (EUROTRAM)
Strasbourg has about 270,000 inhabitants. Also in Strasbourg, as in many cities of western world, trams were removed in 1960 to leave urban space for car traffic and parking needs.
After 30 years, In 1990, to solve the problems created by phenomenon Mass Motorization (increasing traffic and pollution) it was decided to build a new Public Rapid Transit system.
Renzo Emili
5. KARLSRUHE (TRAM-TRAIN NETWORK)