Commuter Rails and Buses

Commuter rails and buses offer the advantage of carrying many commuters on the same vehicle on a single trip so that fewer personal cars crowd the roads. Commuter rails have evolved over the past 100 years to encompass a variety of styles seen in cities today. Some large cities contain more than one mode, and almost all large U.S. cities contain at minimum a bus system and a rail system. The table on page 49 explains the types of rail systems in use in the world today; all have in common the requirement of running solely on set routes determined by preexisting tracks.

Heavy rail refers to railroads that carry freight and passengers coast to coast. Some railway lines combine freight cars and passenger cars, but others such as Amtrak trains run mainly for long-distance travelers and commuters. Local commuter rails, such as New York’s Long Island Railroad (LIRR), cover shorter distances, and, in many instances, these local lines
bear the majority of rail travel in a metropolitan area. For instance, the LIRR carries almost 300,000 commuters each weekday and is the busiest commuter railroad in North America.

The difference between heavy rail and light rail can be difficult to understand at times because many light rail systems serving cities and suburbs resemble long-distance commuter rails. The following two principles have helped clarify the difference between light and heavy rail, but even these principles have exceptions and may be thought of as merely rough rules of thumb. For instance, most subway riders board trains from a platform.

1. Light rail travels 10 miles per hour (16 km/h), up to 60 miles per hour (96 km/h), and heavy rail travels faster than 60 miles per hour.
2. “On heavy rail, you board the train from a platform. On light rail, you board the train from the ground.” (engineer Harry H. Conover)

Trolleys, streetcars, and trams differ from rails because they usually travel at low speeds, and they often receive electric power from lines above the car. These modes alleviate some downtown congestion, but they may also contribute to traffic congestion in certain places such as crossings.

Light rail covers longer distances from outlying areas to city centers and presents the best features for getting people out of their cars and onto mass transit. Light rails usually travel on tracks in which the electrical power comes from a dedicated power rail in the track, sometimes called the third rail. Traffic design engineers now develop light rail systems that
share some of the characteristics of streetcars and trams, such as routes along mixed traffic streets, dedicated rights of way, exclusive corridors, or in the middle of major thoroughfares.

Light rails are easier to build than heavy rails and have lower operating costs. These advantages enable engineers and local governments to plan convenient routes to reach commuters yet avoid wetland and woodland environments. Light rail and subway systems hold great potential for conserving fuel in urban areas and reducing harm to the environment, especially by incorporating the following points:

1. different types of systems to expand commuter choices
2. convenient stations
3. convenient commuter-hour scheduling
4. on-time performance
5. minimize breakdowns
6. preservation of open space

Commercial bus lines strive for similar objectives as light rail systems, that is, moving large numbers of people swiftly on a single vehicle. Longdistance bus companies such as Greyhound run intercity bus lines, while transit buses (also called urban or city buses) serve neighboring towns or a single large city. Buses have two advantages over light rail: (1) buses often serve rural communities where no other mass transit system runs, and (2) bus routes can be changed according to a community’s needs. Like light rail, buses carry as many as 100 passengers on a single vehicle (also called a motor coach, omnibus, or autobus), which spares roads and fuel, but they also congest urban traffic and produce emissions. Unfortunately,  buses have a long history of running on diesel fuel or gasoline and so have contributed to greenhouse gas buildup.

Towns in the United States have made efforts to convert their public buses and school buses to cleaner technologies. Lynn, Massachusetts, for example, plans to retrofit by 2010 all its 5,500 school buses so that filters clean pollutants out of engine exhausts. Ed Coletta, spokesperson for the state’s Department of Environmental Protection, said, “These buses are
going to be used long into the future, and we want to make sure they’re emitting as few gases as possible.” Lynn joins hundreds of other communities that have tried to balance the advantages and disadvantages of buses with a hopeful future.

New clean technologies can apply to vehicles in addition to transit, school, and shuttle buses. The DOE’s Energy Efficiency and Renewable Energy Program keeps track of various public transit fleets that have made similar inroads into pollution control and alternative fuels: delivery services, long-haul trucks, refuse haulers, taxis, rental cars, and police vehicles. All of these vehicles offer the advantage of belonging to fleets that return to a central base so that mechanics can assure the vehicles receive proper maintenance and fueling. The following table describes innovations that are rapidly emerging in public bus fleets.

Advanced transit represents a new type of bus or rail travel that uses more than one technology for the purpose of conserving energy and fuel. For example, a community that is trying to use energy and resources in a sustainable manner may develop an advanced transit system, also called light transit, that contains the following features:

1. a network of interconnected mass transit routes for buses, light rail, and heavy rail
2. dedicated commuter lanes
3. alternative fuel-powered fleets
4. electrical power hookup stations in addition to the fleet’s base station
5. express routes to bypass local station stops
6. emphasis on speed throughout the network
7. accommodation for bicycles in all fleets
8. easy and fast line switching, including long platforms and wide doors

Using the features above, advanced transit can meet its goals of eliminating inefficient schedules and excess fuel consumption, all while providing an enjoyable experience for riders. To do this, future advanced transit systems will likely include vehicles that are not yet common in today’s mass transit, such as trams, light-duty buses, dedicated bicycle
and scooter routes, and extensive use of car- or bike-sharing in city centers.