What are urban light rail networks?

11.4.2.2 LRT (Light Rail Transit)

The LRT vehicles usually consist of 2–3 cars operating at an average speed of 55–60 km/h on the lines with more dense stops/stations and 65–70 km/h along the lines with less dense stations. The LRT service frequency is usually adjusted to demand and differs during peak and off-peak hours of the day—maximally from 12 dep/h (every 5 min) to 4 dep/h (every 15 min) during the day and 1–2 dep/h (every half or an hour) during the night.

Such operational patterns generate noise by each individual vehicle and the successive vehicles from the sources similar as the streetcar (tramways) such as the wheel/rail noise, the noise from the vehicle traction motors, the noise from the vehicle's auxiliary equipment (ie, air conditioning, compressors, and motor controllers), and warning devices.

For example, some measurements have shown that the LRT vehicle operating at the speed of 80 km/h creates the maximum level of noise Lmax = 80 dBA at the distance of 15 m from the tracks. In addition, Fig. 11.24 shows relationship the level of noise and speed for the LRT vehicles. The noise from other vehicles has been given for the comparative purposes (Janić, 2014a,b).

As can be seen, the noise from LRT increases at decreasing rate with increasing of the vehicle's operating speed. At the same time, the noise level of LRT vehicle is greater than the noise level generated by other urban and sub-urban transit vehicles/systems/modes at any speed mainly due to the shorter distance between the vehicle and the observer. In addition, at the speed of 80 km/h, the LRT vehicle noise has increased for about 3 dBA with decreasing distance from 15 to 3 m. The LRT vehicles also generate noise from on-board warning devices including gong, bells, and horn. The gong or the bells are used for alerting when the LRT vehicles enter a station to alert passengers on the platforms of oncoming vehicles. The louder horns are used at grade crossings. The maximum sound levels obtained at the distance of 3 m has measured to be 75 dBA by the gong, 95 dBA by the bells, and 112 dBA by the horn. In addition, by using the LRT source noise levels, the average hourly daytime and night time operations, and speed, the LRT pass-by hourly and daily noise levels can be estimated (KMCEI, 2007).

2.4.2.4 LRT system

The LRT system has also been complementing or in some cases a predominant if not an exclusive mass urban and/or suburban transport system for passengers. In the former case, it has often operated as a complement to the urban metro systems and the regional rail systems as well. In the latter case, it has been as a backbone of the public transit system as shown in Fig. 2.13 (Kishimoto et al., 2007; Vuchic, 2007; https://www.google.nl/search?q=images+of+LRT+networks).

In general, the spatial layout of the LRT infrastructure networks have been mainly influenced on the area, size, and density of population, and the presence of the other urban transit modes serving the same urban and/or sub/urban areas. However, in many cases, it has not been easy to make a clear distinction between a streetcar (tramway) and LRT system. The main distinctive characteristic has related to the systems' infrastructure lines and networks. In the case of streetcars (tramways) share their rights-of-way with cars fully or partially, while LRT trains mainly operate along their right-of-ways. This enables providing higher quality of transit services in terms of travel speed, punctuality, and reliability. However, both systems have the similar vehicles with slightly distinctive capacities operating along the lines with different interstation distances in particular parts of a given urban/suburban area—the streetcar (tramway) with generally shorter, and the LRT system with generally longer—ones. Fig. 2.14 shows a simplified scheme of these characteristics.

As can be seen, in these cases, the streetcar (tramway) system tends to have more distant, ie, less frequent, stations along parts of its lines spreading out of the city center. The stations are closer to each other, ie, more frequent, along the same lines within the city center. The LRT usually has more distant, ie, less frequent, stations along the entire length of its lines.

The scale of operation of the LRT systems has often been considered together with that of the streetcar (tramway) systems, just because of the above-mentioned complexity of making a clear distinction between the two, at least in that statistical context. Therefore, the self-explanatory Table 2.2 gives characteristics—length of network, size of fleet, and the annual volume of served passengers by some largest LRT and streetcar (tramway) systems in Europe (UITP, 2015).

Table 2.2. Some Characteristics of the European largest LRT and Streetcar (Tramway) Systems (UITP, 2015; http://www.railway-technology.com/projects/category/light-rail-systems/)

As can be seen, the longest network has been in St. Petersburg (Russia), the largest LRT/streetcar (tramway) fleet has been operated in Prague (Czech Republic), and the largest annual volume of satisfied passenger demand has been in Budapest (Hungary). It should always bear in mind that these figures relate to the integrated figures of both LRT and streetcar (tramway) systems (UITP, 2015).

10.5.1.3 BRT and LRT

The construction costs of BRT and LRT system infrastructures have always been considered as a strong criterion when the decisions which system to further develop or implement in given urban areas have to be made. This is because both systems have been comparable regarding other (operational and economic) performances, while satisfying expected passenger demand under given conditions. In addition, these costs of both systems have shown to be inherently very diverse in various urban areas. This diversity is caused mainly by differences in the local physical conditions for building the infrastructure, as well as by the costs of inputs for undertaking the activities in terms of labor, material, and energy. Fig. 10.7 shows the total cost of constructing BRT and LRT infrastructure/lines in dependence on their length in the urban areas in the United States (GAO, 2001).

As can be seen, at the LRT systems, these costs have generally increased with increasing of the length of lines. However, the differences have been considerable: for example, to build the line of length of 25 miles, the costs have varied from about 0.3–1.0 × 1010 $US. At the BRT systems on busways and HOV (high-occupancy vehicle) lanes, these costs have mainly varied from 0.01 to 0.2 × 1010 $US for the length of lines from about 5 to 20 miles. At the BRT systems on arterial lines these costs have been much lower for the same range of length of lines. Table 10.3 gives the aggregate figures on the total length, and total and average construction costs for the above-mentioned BRT and LRT systems.

Table 10.3. Examples of the Construction Costs of the LRT and BRT Systems in the United States (GAO, 2001)

LRT, light rail transit; BRT, bus rapid transit.

As can be seen, the average unit construction costs of LRT system has been particularly for about three and four times greater than that of BRT systems on busways and HOV lanes, respectively.

5.5 Energy Efficiency Potential from Intermodal Operations

As illustrated in Table I, high-capacity, heavy metro and LRT systems can be very efficient, energy-wise, when operated at high passenger loads, and conversely, can be extremely inefficient during periods of low passenger flow. Figure 5 illustrates the effect of load on energy efficiency as the passenger load decreases in (1) a 150-passenger LRT vehicle and (2) 10 ULR vehicles, with the ultralight vehicles being removed from service as the load decreases.

Ultralight rail systems have the potential to increase the energy efficiency of high-speed and heavy rail systems by feeding extra passengers into existing stations from outlying areas off the sides and ends of the high-capacity systems. Figure 5 provides an example of the increase in energy efficiency possible by the intermodal connection of conventional rail systems and ultralight rail, where a single ultralight passenger load is brought in from the side or end and added to the passenger load of a conventional LRT-size vehicle.

Additional passengers brought in from the side or ends of conventional systems by small ultralight vehicles not only increase the energy efficiency of the conventional systems, but reduce the need to provide additional parking in the immediate station area. Parking for the ultralight systems can be placed far from the conventional system stations in less expensive and more accessible real estate.

Conventional heavy metro and LRT systems are expensive ($50,000,000 to $100,000,000 per mile) and have a large ground footprint, two characteristics that detract from extending the systems into lower density sources of passengers. Additionally, it is not only expensive to provide parking around stations, where the land is at a premium, but 5 acres of expensive parking can hold only ∼750 vehicles, approximately the passenger capacity of one heavy metro train. Therefore, the first train through the system can take all of the parking lot patrons, leaving the station isolated to many potential passengers and lowering the efficiency of the large transit system. Ultralight systems that cost $10,000,000 to $20,000,000 per mile and have a much smaller ground footprint can be extended far beyond the walking limits of conventional rail stations, bringing additional passengers to the conventional system in an energy-efficient process, making the operation of the conventional system even more efficient, since the marginal energy cost of additional passengers on a conventional system is extremely low.

4 Self-Launching gantries for span-by-span erection of precast segments

Span-by-span erection is used for precast segmental spans shorter than 50 m in highway bridges and 30–45 m in light-rail transit (LRT) bridges. The gantry is loaded with all the segments for the span to stabilize the deflections during gluing. After prestress is applied, the support jacks of the gantry are retracted to release the span in one operation. A typical 40-m span with epoxy joints is erected in 2–3 days.

Overhead or underslung gantries are used for span-by-span erection (Rosignoli, 2013). A twin-girder overhead gantry comprises two trusses or box girders supported on pier cross-beams (Figure 27.3); auxiliary pendular legs are necessary to erect the pier-diaphragm segments of continuous spans and to reposition the support cross-beams without ground cranes. A portal crane bridging the main girders lifts and moves the segments into position and avoids interference with segment hangers during launch.

The overhead gantries are not much affected by ground constraints, straddle bents, C-piers, or variations in span length and deck geometry. They are more complex to design, assemble, and operate than the underslung gantries, and they are also more expensive and slower for erecting the segments with spreader beams.

If the segments are delivered on the completed bridge, the winch-trolley picks them up at the rear end of the gantry and moves them forward into position. If the segments are delivered on the ground, the winch-trolley lifts them up to the deck level. Hangers and spreader beams are used to hold the segments in position during assembly and gluing.

Pier cross-beams support the gantry with articulated saddles that allow longitudinal and lateral movements and rotations about the transverse and vertical axes. Some support saddles lodge longitudinal lock systems for the gantry, and all the cross-beams are equipped with transverse lock systems. The cross-beams are anchored to the pier caps with stressed bars that resist uplift forces and provide friction transfer of lateral loads.

Some light gantries are launched with winches and capstans. Hydraulic cylinders lodged within the support saddles and acting against racks anchored to the trusses provide higher thrust forces and safer operations. Paired launch cylinders are often used for redundancy.

A single-girder overhead gantry takes support on the leading pier of the span to erect and on the front-pier diaphragm of the completed bridge. The front support legs are often framed to the main girder, and the rear portal frame rolls over the new span during launch. Special launch systems suspended from the main girder are used to reposition the gantry. These machines are shorter and lighter than the twin-girder overhead gantries, and there is a better fit for curved bridges.

Some first-generation overhead gantries were equipped with stay cables. Cable-stayed gantries have been abandoned over time in spite of their structural efficiency, as the cables complicate operations and increase labor demand. Trusses of varying depths are also rarely used for span-by-span erection nowadays.

Telescopic gantries are used to erect dual-track LRT spans with tight plan curvature (Figure 27.4).

A winch-trolley is suspended from the main girder, and the segments are delivered on the ground or on the completed bridge through a rear portal frame. The gantry comprises a rear main girder and a front underbridge. A turntable with hydraulic controls connects the main girder to the underbridge. During the first phase of launch, the turntable pulls the main girder over the underbridge. When the front support legs of the main girder reach the new pier, the underbridge is launched to the next span to clear the area under the main girder for erection of the new span.

Many precast segmental bridges have been erected with underslung gantries (Figure 27.5). These machines are positioned beneath the deck, with the main girders on either side of the piers. The gantry supports box girder segments under the side wings, with hydraulic carts for control of camber and cross-fall. The main girders take support on pier brackets or cross-beams hung from the pier caps. When the piers are short and slender, the pier brackets may be propped from foundations.

Ground cranes or lifting frames are used to load the segments onto the gantry. When the segments are delivered on the completed bridge, the lifter is placed at the rear end of the gantry. When the segments are delivered on the ground, the crane is placed at the front end of the gantry. The segments are loaded onto the gantry close to the lifter and rolled into position. A portal crane may also be used to lift the segments and move them into position. Upon application of prestress, the gantry is lowered to release the span in one operation.

The underslung gantries are not very compatible with curved bridges, as the main girders conflict with the piers and the completed spans. The front end of the girders may be connected by a cross-beam that rolls along a central underbridge during launch. A rear portal frame rolling on the new span may be used to further shorten the rigid portion of the machine. New-generation gantries with articulated girders have also been used for curved spans.

The underslung gantries are simple to design, assemble, and operate. Span erection is fast, and props from foundations can be used to increase the load capacity when working low on the ground. These machines project beneath the deck, which may cause interference with straddle bents and C-piers, clearance issues when overpassing active infrastructures, and difficulties at the end spans of the bridge.

44.2.1 Introduction

Such has been the rapid development of light rail technology that inevitably it has become subject to many misconceptions. It has also been heavily oversubscribed in written terms and has therefore been the subject of transport ‘hype’. It has varyingly been referred to as light weight railway suburban stock at one end of the scale and as an up-market successor to the tram on the other. Whilst in the formative years there is an element of truth in this sort of statement, nevertheless the developing forms of transport have crystallised into its recognisably present status of light rail transit.

Present day light rail transit systems fall into a number of defined categories—the older systems used in many parts of the world (particularly Europe), and the new systems to be found in the UK and the USA, where the public transport renaissance is most marked. These new systems have greatly benefited from the new technologies manifest in traction power supply and collection, suspension and running gear, and control and traction equipment, but in many respects more importantly in the public recognition of the advantages of light rail transit in a country where urban and peri-urban congestion with its environmental pollution, noise, congestion, and attendant loss of working hours has taken dramatic toll of our lifestyles. The new system with light-bodied energy-efficient vehicles and effective operating specification is now firmly established.

The new systems originate from the 1920s and 1930s where, in the UK, design and construction was fragmented and standards were at variance. This situation was rectified in the early 1930s by introducing standard types of tram, mainly as a standardised product in the USA arising from the President's Conference Committee. The present light rail transit systems are designed to form an integral link within an overall transport system. They will support the distributive role which the motor bus still fulfils and provide a fast and efficient carrier system between centres of population, as well as an interface with heavy rail systems.

7.3 Urban Public Transit

Urban public transit enables people’s movement in cities and in many cases also in suburban areas. They include demand-responsive and mass transit systems. The former are taxi systems and dial-a-ride systems. Taxi system uses operating individual passenger cars and sometimes small vans. They are the real-time demand-responsive systems, which provide transit services starting from the location/origin of the person’s request/call and ending at his/her desired destination. They use the urban streets and regional roads as the infrastructure network.

Dial-a-ride systems exist in some areas with lower population densities. The planned trip has previously to be announced that it is necessary to make a reservation. Such systems are also often used to transport the elderly and citizens with disabilities (Fig. 7.3).

There are also public transportation forms that combine fixed route systems with demand-responsive transportation (DRT) systems.

The mass transit systems operate according to the schedule by transporting a larger number of persons/users/passengers simultaneously being onboard of the larger vehicles—generally buses and trains (Vuchic, 2005). It is a shared transportation service since many passengers are carried in the same vehicle. The phrases “mass transit,” “public transportation,” and “public transport” are also used to describe this type of transportation service (Vuchic, 1981; Desaulniers and Hickman, 2007). The fixed-route system is the most common public transportation system in many cities in the world. It is characterized by high values of the number of requests for travel between the nodes in the transportation network. The vehicle routes are fixed, and the vehicle schedule is the same every working day.

There are two groups of public transportation users. The first group consists of people that have also other opportunities to travel. These are vehicle owners who choose public transportation, due to savings in transportation costs, and/or potential problems with parking. Most frequently, drivers become passengers in public transportation with the idea to avoid traffic jams. In big cities like New York, the majority of morning commuters arrive downtown by public transportation.

The second group of public transit users represents users who cannot drive private cars. Even in many developed countries, up to a third of the population cannot drive a private car. The very young, the elderly, citizens without a valid driving license, citizens who do not own a car, and citizens with disabilities need to use public transportation services.

Public transportation uses group travel technologies (trolleybuses, buses, trams, trains, ferries, etc.). Public transport can play an extremely important role in decreasing traffic congestion and air pollution reduction in many cities globally.

It is well known that, in most cases, it is not easy for public transit operators to make a profit from this activity. Asian public transit operators are mainly privately owned companies, while the transit operators in the United States and Canada are usually run by municipal transit authorities. The European public transit operators are run by municipal transit authorities, as well as by state-owned companies.

The authorities in charge of public transportation try primarily to increase the mobility of the urban population. The city authorities attempt to provide to the passengers the best possible level of services within the available budget. Public transportation operators are interested, first of all, in serving all the planned trips with the minimum possible number of buses and/or the minimum transportation costs. Together with passengers, the agencies and operators are interested in small waiting times at bus stops and at transfer points, satisfactory comfort in vehicles, etc. Passengers are also very interested in high service reliability that represents the degree to which buses provide punctual service.

Public transportation vehicles serve groups of unconnected passengers. It is not an easy task to collect trips in space and time efficiently. Consequently, one of the most important problems in public transportation that has to be solved is the problem of matching transport capacities and passenger demand. Public transit network topology, vehicle frequencies, as well as distribution of departure times on specific routes represent the manner in which passenger demand and transport capacities are matched.

The horse-drawn omnibus is the first known public transit system. The transportation service with the horse-drawn omnibus started in France in 1828. Rails in the street, cable cars, steam and electric trains, and elevated rail transit lines appeared in the 19th century (Fig. 7.4).

An electrified rapid transit train system appeared in the second part of the 19th century in London. Today, there are more than 160 metro systems in the world. Carpools, fixed bus routes, light rail, heavy rail, aerial tramway, cable car, trolleybus systems, and automated guideway transit (AGT) are some modern public transportation systems (Fig. 7.5).

Some of these forms share right-of-way (ROW) with private cars, while some others have dedicated ROW. The public transportation forms also differ due to the technology used for guidance, size of the cabin used, the type of fuel used, and the type of routes and vehicle schedules.

Taxis and dial-a-ride systems have low capacity. The medium capacity is related to buses, trolley buses, and trams, while light rail transit and rapid rail transit are considered to be high-capacity transportation modes.

The mass transit systems can be the road- and rail-based transit systems consisting of the infrastructure and the service networks generally characterized by the technical/technological characteristics. The technological characteristics are as follows: ROW category (any or exclusively intended path for operating public transport vehicles), support (type of vehicle’s wheels—rubber tires or steel), guidance (steered or guided), propulsion (internal combustion engine, electric), control (manual, semiautomatic, and fully automatic), and transit unit (small, medium, and large vehicles, and short and long trains). Public transit is accessible to the general public in many cities in the world. The elements of the urban public transit are vehicles (buses, trolleybuses, trams), ways (streets, tracks, guideways), stops (stops, stations, terminals), garages, power supply systems, and control systems.

Road transport modes include regular buses (RB), trolleybuses (TB), and semi-rapid buses (SRB), and their derivatives/modifications. The rail transport mode includes streetcar (STC) or tramways, light rail transit (LRT), rail rapid transit (RRT) or metro, regional rail (RGR), and their upgrades/modifications. It should be pointed out that the LRT and PRT systems and their particular liens/routes have been increasingly semi- and/or fully automated, i.e., driverless, in many urban areas around the world (Vuchic, 1981, 2005).

7.3.1 Road-Based Urban Transit Systems

7.3.1.1 Regular buses

This road-based medium-capacity urban transport system consists of buses operating along fixed routes and according to the fixed, announced in advance, schedule with relatively frequent/dense stops along the lines/routes. The public transportation systems based on bus operations have the lowest investment cost per line length. Simultaneously these systems have the lowest performances. Buses serve passengers in many cities in the world. The capacity of buses in terms of spaces (seats and stands) for passengers can vary from that of the minibus (25–30) and standard bus (80) to that of the long (articulated) bus (120–125) (EU, 2011). This transit system is very flexible due to the ability of buses to operate along almost all streets and roads in urban and suburban areas. In addition, they can change the layout of the line/route by changing particular streets and roads they follow due to any reason (Fig. 7.6) (Vuchic, 1981).

Fig. 7.6. Typical bus used in public transit (http://www.everystockphoto.com/).

7.3.1.2 Trolleybuses

This is another road-based medium-capacity urban transport system very similar to the abovementioned bus system including the capacity of vehicles-trolleybuses. The exception is that trolleybuses are propelled by electric power obtained from two overhead wires spreading along their lines/routes. Such ultimate energy-power dependency reduces the spatial flexibility of the system’s lines/routes to adapt to the spatial changes due to any reason. The system also operates the transport service network along the streets and roads in urban and, in some cases, also in the suburban areas, respectively (Fig. 7.7) (Vuchic, 1981).

Fig. 7.7. Trolleybus used in public transit (http://www.everystockphoto.com/).

7.3.1.3 Semirapid buses

This road-based high-performance system operates high-performance buses of the similar capacity as its regular counterpart, usually along with the dedicated (reserved) paths—lanes—along the streets and roads in urban and suburban areas. The transport services are carried out according to the fixed schedule. The number of stops along the lines/routes is smaller than that at the abovementioned RB system. An improvement of the Regular and particularly SRB system has been the development of the BRT (Bus Rapid Transit) system. As a flexible rubber-tired road rapid transit system, it combines stations, vehicles, services, running ways, and ITS (intelligent transport system) into an integrated system with a strong positive image and identity. In particular, the system uses the concept of HOV (high-occupancy vehicles) and the new/innovative vehicles-buses compared to those of its conventional counterparts. They operate along the strictly reserved existing and new-built bus lanes on streets, bus/pedestrian malls, and other roads while having priority treatment at intersections. In many respects, BRT can be considered as a rubber-tired LRT-like system but with greater operating flexibility and potentially lower capital and operating costs (Levinson et al., 2003). The system has shown flexibility in terms of feasibility of implementation in urban areas with a population of between 0.2 and 10 million. As such, in many transit corridors/routes, it has represented a test bed before implementing a rail-based urban transit system such as LRT (Fig. 7.8) (Janić, 2014; Vuchic, 2005).

Fig. 7.8. Bus rapid transit.

7.3.2 Rail-Based Urban Transit Systems

7.3.2.1 Streetcars or tramways

This is a rail-based medium-capacity urban transit system operating electrically powered vehicles usually in the composition of 1–3 units, with the capacity of 100–300 spaces for passengers. The layout of the line/route is determined by the alignment of the rail tracks located mainly along the dedicated lanes of particular streets and roads in urban areas. The electricity is provided by the single wire above the line/route, i.e., tracks. However, in many cases, these lines/routes have shared the same streets and road lanes with other transit modes and individual cars, which often caused congestion and considerable friction with each other, particularly with individual car traffic. The transit services are provided according to the fixed schedule with the number of stops along the lines/routes similar to that of the RB system. As such, this system has been competing and later on complementing the RB systems in many urban areas (Fig. 7.9).

Fig. 7.9. Tramway used in public transit (http://www.morguefile.com/).

7.3.2.2 Light rail transit

This is the rail-based high-performance urban transit system operating trains along predominantly reserved grade-separated ROWs—tracks. The trains are electrically powered, consisting of 1–4 vehicles/cars providing the capacity of a train of 110–600 spaces for passengers. The services are provided according to the fixed schedule at stops/stations, which are rarer than those at bus and tramway systems. This system possesses some advantages and disadvantages regarding the spatial flexibility of its lines/routes: on the one hand, it can run on the grade-crossing tracks, and also on the streets, which increases its spatial flexibility; on the other, the layout of its lines/routes remains ultimately inflexible following the alignment of tracks. In addition, the system has originated as a substantive upgrade of Streetcar or Tramway system, but it also possesses the ability to be upgraded into a rapid transit system, such as Light Rail Rapid Transit (LRRT) or RRT. After being fully automated, i.e., driverless, the LRRT system has also become known as Automated Light Rail Transit (ALRT) (Fig. 7.10) (Vuchic, 2005).

Fig. 7.10. Light rail transit (http://www.everystockphoto.com/).

7.3.2.3 Rail rapid transit or subway or metro

The London Underground, the first metro system in the world, was opened in the second part of the 19th century. Nowadays, there are approximately 160 metro systems in 55 countries in the world. Metro has the highest investment cost per line length. This is the rail-based high-performance urban transit system operating trains along the dedicated lines/routes with rail tracks usually spreading underground, i.e., with the tunnel alignment in the large densely populated urban areas. The electrically powered trains are composed of 1–10 vehicles/cars with the capacity of 140–2000 spaces for passengers. The transit services are provided according to a fixed schedule with relatively close stops at underground stations in dense urban areas and fewer stations in suburban areas. Compared with its abovementioned LRT counterparts, the RRT system provides much higher transit capacity, travel speed, internal comfort, reliability, punctuality, and safety of services. Similarly as in the case of LRRT systems, the particular lines/routes or the entire network/system has been also increasingly semi- or fully automated (Fig. 7.11) (Vuchic, 2005).

Fig. 7.11. Metro (http://www.morguefile.com/).

7.3.2.4 Regional rail

This is the rail-based high-performance suburban transit system, which operates trains along the rail lines/routes spreading between urban and suburban areas. These usually electrically powered trains are composed of 1–10 vehicles/cars with the capacity of 140–1800 spaces for passengers. The transport services are provided according to the fixed schedule, at lower service frequency and the rarer stops at stations on the longer lines/routes. Thanks to the longer lines/routes and rarer stops, the travel speed of RGR trains is higher than that of the abovementioned RRT and LRT counterparts (Fig. 7.12) (Vuchic, 1981, 2005).

Fig. 7.12. Regional rail.

Modal Energy Use Per Passenger Kilometer (PKT)

Table 3 provides the energy consumption per PKT for each mode in the 44 cities, while Table 4 summarizes the regional differences and the changes from 1995–96 to 2005–06. Clearly, public transport in all groups of cities consumes significantly less energy per PKT than private transport. However, it must also be noted that in Denver, New Orleans, Phoenix, and Seattle, public transport energy use per PKT in 2005 exceeded that of private transport. In 1995, this surprising situation did not exist in any US city, although in Phoenix and Denver the values for private and public transport were very similar. However, with improvements in car fuel efficiency and insufficient passenger loadings on public transport in these four car-oriented cities, public transport energy use per PKT has risen above private transport. The critical nature of passenger loadings on public transport’s energy benefits can be seen in America’s most transit-oriented metropolitan area, New York, where average energy use per PKT is low and close to many European cities. In addition, the gap between private and public transport energy use per PKT in New York is the greatest of all US cities.

Table 3. Modal Energy Use Per PKT in 44 Cities, 2005–06

Table 4. Changes in Modal Energy Use per PKT by Region, 1995–96 to 2005–06.

In all but a few isolated exceptions, rail modes in every city (tram, LRT, metro, suburban rail) have lower energy consumption per PKT than regular buses, and certainly than minibuses. For the most part, minibuses are in US cities, providing bus services of marginal quality (often demand responsive) with poor ridership in low density, peripheral areas (their energy consumption in 2005 was 7.68 MJ/PKT compared to 2.09 MJ/PKT for American urban public transport modes overall and 2.97 MJ/PKT for regular US urban buses). Rail modes mostly consume less than 1.0 MJ/PKT, while ferries frequently consume the most energy per PKT of all modes, again with some exceptions (e.g., where ferries are very small, as in Vancouver, or of moderate size, but very well-utilized, as in Zurich).

The most common rail mode across the 44 cities is suburban rail. In US cities, suburban rail energy use per PKT was 55% lower than private transport and in Australian, Canadian, European, and the two Asian cities it averaged 83%, 69%, 74%, and 92% less, respectively. On the other hand, bus systems in US cities were on average 4% higher in energy use per PKT than private transport (2.97 MJ/PKT compared to 2.85), while in Australian, Canadian, European, and Asian cities respectively, buses were 35%, 59%, 43%, and 71% lower than private transport. Low passenger loadings and high energy use per bus VKT in American cities are clearly problems.

Table 4 shows that from 1995–96 to 2005–06, energy consumption per PKT in private transport declined in all groups of cities except those in Australia, and the various rail modes in all groups of cities also mostly showed reductions. Averaged across all cities, the only rail mode that showed a small increase in energy use per PKT was LRT (4.3%). On the other hand, the same factor for buses rose in every group, and for the whole sample, increased from 1.63 to 1.78 MJ/PKT (a 9.8% increase). As shown later, a major factor behind the better energy performance of rail modes, not only in their reductions in energy use over the decade, but also in their comparative superiority over buses, lies in a global renaissance in the usage of urban rail systems, while buses in many cases struggle to compete (Newman et al., 2013).

The speed disadvantage of buses in cities compared with cars is caused predominantly by uncontrolled, low occupancy car driving, which consumes most available road space. This results in buses, which have much higher occupancy than cars and take up a fraction of the road space, being stuck in the traffic congestion caused by their space-consumptive competitors. Bradley and Kenworthy (2012) provide a detailed analysis of this problem on technical, equity, and policy grounds, and offer some innovative solutions to help buses compete better (and reduce their energy use). Newman and Kenworthy (2015: 93–94) provide a detailed quantitative example from São Paulo demonstrating the inequity and dysfunctionality of allowing buses to remain stuck in traffic congestion.

Finally, Table 4 reveals that private transport energy use per PKT averaged across all the cities fell by 5.3%, while public transport increased by 0.9%. However, despite what are mostly technological gains in the fuel efficiency of cars over 10 years, private transport remained approximately 2.3 times more energy consumptive per PKT than public transport (2.72 compared to 1.16 MJ/PKT), though down a little from 1995, when it was 2.5 times more.