Light Rail vs. Trolley Bus

Looking at adding electric power? See how one system uses both.


With fuel prices on the rise and concerns about climate change, traffic congestion and parking weighing increasingly on the minds of commuters, transit systems across North America are looking for ways of convincing people to leave their private vehicles at home. In the course of their deliberations, the minds of planners may drift toward systems that don’t use fossil fuels — systems such as electric trolley buses or various forms of electrified rail (light rail transit and others).

Greater Vancouver uses a variety of transit modes, including electric trolleys and automated rail. Electric-powered transit has been a part of the region’s life for more than a century, and Vancouver retains the second-largest electric trolley fleet (after San Francisco) in North America.

In 1897, the BC Electric Co. introduced its streetcar system. The streetcars were followed, not long after, by three interurban tram lines, the longest of which operated from Chilliwack, about 60 miles (90 kilometers) east of Vancouver, through the lower Fraser Valley, and eventually into downtown Vancouver.

By the 1940s, though, tracked systems were starting to fall out of favor, and BC Electric started moving to rubber tires. The first trolley buses — Brill buses, built by Canadian Car and Foundry in what is now Thunder Bay, Ontario — went into service in 1948 and by the mid-50s the streetcars and tram were gone.

The Brills were gradually retired in the mid 1970s and replaced by new trolleys built by New Flyer Ind. of Winnipeg. These coaches were replaced in the early 1980s with a newer model from Flyer, using new motors and solid-state controls. The majority have been in continuous service for 25 years. Late last year, the first of a new generation of trolleys, built by New Flyer with propulsion systems by Vossloh-Kiepe of Germany, began operating on Vancouver streets. In total TransLink will take delivery of 228 new trolleys, including 40 articulated coaches. A dozen of TransLink’s 200-plus routes are served by trolleys.

After a lull, which lasted more than 30 years, rail began regaining importance in Greater Vancouver’s transportation system. Plans began in the mid-1970s for a rail-based rapid transit system and the result was SkyTrain, introduced in 1986 for Expo 86, the transportation-themed World’s Fair.

SkyTrain is a driverless, fully automated, grade-separated system. Today, the first SkyTrain line, now known as the Expo Line runs from downtown Vancouver, through Burnaby and New Westminster to Surrey, about 18 miles (29 kilometers) to the southeast. It hits speeds of 50 miles per hour (80 kilometers an hour) on an elevated guideway about 30 feet (10 meters) above ground except for about a half-dozen stations, which are underground or just below street level.

A second SkyTrain line — the Millennium Line, which opened in 2002 — covers a 12-mile (20-kilometer) route around the northern portions of Burnaby and New Westminster, integrated into the original Expo Line.

A third rapid transit line, the Canada Line, is now under construction and will open in 2009.

Rubber-tired Trolleys
A look at trolley buses and urban rail shows each system has its advantages and its drawbacks. In general, electric trolley buses outdo diesels in performance. They have superior power when fully loaded and good acceleration on hills. They also have a much quieter ride.
The initial move to trolleys in the 1940s came because gasoline buses were still not ready for prime time. The streetcar overhead was already in place, readily converted to the dual-wire trolley bus overhead. Since BC Electric, the province-wide power utility (now government-owned BC Hydro), owned and operated the bus system, investing in electric trolleys made sense from a financial point of view too. The quieter, pollution-free electric buses — streetcars without the rattling and clanging — were a big hit.

With the significant investment in infrastructure, it made sense to continue with electric trolley buses in the 1970s when the original Brills started being retired and to continue as the new generation is phased into service.

Trolley buses have a high initial price. Because of the sophisticated technology and the fact that, with only seven North American cities still using trolleys, relatively few are built, the sticker reads just under US $1 million each. That’s more than twice the price of a new diesel bus. That being said, trolleys last longer. Diesels of the same basic design, which were purchased in the early ‘80s, are long gone. Trolley buses bought at the same time are only just now being retired. The trolley infrastructure costs about US $1.3 million per mile for the overhead alone. On top of that is the cost of substations to distribute the 600v DC power. However, with high-efficiency electric motors, plus regeneration of some power back into the overhead grid during braking, trolleys shine in overall energy impacts. It costs approximately 20 cents per mile to power an electric trolley bus (ETB) compared with about 75 cents per mile for diesels averaged over TransLink’s entire diesel fleet.

The city of Vancouver also has the advantage of being a peninsular city and therefore there were natural boundaries for the trolley bus system when it was introduced in the late 1940s. This has kept trolley buses confined to the city, except for one route, which travels about three-quarters of a mile into the city of Burnaby. The majority of the corridors served by trolley buses — nine of the 14 — run north-south; four run east-west and one more runs diagonally, northwest to southeast. Furthermore, Vancouver has a strong city center, and did not introduce extensive one-way streets or new freeways, so the original network of routes has remained largely intact.

Not all of Vancouver’s trolley bus routes are served solely by trolleys, so it’s not possible to get an accurate figure on the number of passengers they carried in 2006, but buses based at the Oakridge Transit Center, where all the trolleys are located, recorded 90.7 million boardings — the equivalent of more than 72.5 million car trips.

One drawback to trolley buses is the fact that they are literally tied to their overheads. That means that if there’s a traffic problem, they’re often stuck in it. The new New Flyers have a more powerful battery-powered auxiliary motor, which allows them to have their poles pulled and skirt around things that encroach on their lanes, but those motors are only designed for short bursts, perhaps as far as three-quarters of a mile (1 kilometer), depending on grade and loading. This means they cannot re-route for long distances or at a moment’s notice the way diesels can. Dedicated bus lanes and traffic signal priority do help in getting buses past heavy traffic, and these are being phased in on some major routes.

Increasing traffic congestion has put the brakes on any expansion of the trolley system as the Greater Vancouver region has grown. Growth over the past 30 years has been phenomenal, from a population of 1.1 million in 1976 to 2.1 million last year. That spread has been eastward, onto large expanses of what had been farmland. Expanding trolley service to meet that growth would have incurred prohibitive costs.

Furthermore, because of the dynamic nature of the region’s growth due to changing neighborhood patterns and traffic disruptions caused by building construction or road upgrading and maintenance, conventional buses (diesel, with a few dozen compressed natural gas buses and a handful of experimental alternative-fuel buses) provide the best flexibility for service delivery.

Aside from their electric tether, trolley buses are also susceptible to power outages. Since they run on separate DC power, their power source is generally different from that of BC Hydro’s regular customers, but on rare occasions, service is shut down by a normal BC Hydro outage. However, trolley overheads are susceptible to their own problems. They can be brought down by snow-laden tree branches, wind or a traffic accident. This past winter, the collapse of several trees knocked out trolley service to the University of British Columbia for more than a week.

Trolley overheads are also susceptible to icing, especially when freezing temperatures hit a climate where moist ocean air is already present. The problem is usually detected before the start of service, so the first runs out of the yard are equipped with ice cutters on the carbons (the contacts at the end of the trolley poles). But the ice cutters can damage the overhead wires, so they must be used sparingly.

Considering the greenhouse impact of electric buses is a bit more complicated. Of course, the buses themselves don’t produce emissions, but one must consider how the electricity is produced. If the power comes from coal-fired plants or other sources regarded as dirty energy, then that has to be taken into account. TransLink’s trolley buses are run by hydroelectric power, which, all things considered, is regarded as relatively clean.

TransLink used a form of carbon offsets to purchase the new fleet of New Flyers. For the past few years, BC Hydro has offered Green Power Certificates (GPCs), which help pay the difference between the cost of conventional electricity production like hydroelectric dams and the cost of green production like windmills, waterfalls and biomass. In order for the Federation of Canadian Municipalities to guarantee a loan at below market interest to buy the buses, TransLink agreed to use the savings in interest payments to purchase GPCs. Thanks to a reduction in BC Hydro’s price for the GPCs and a volume-purchase discount to TransLink, the amount of green electricity produced with those GPCs more than offsets the amount of brown electricity consumed by the new trolleys.

Electric Rails
As for urban rail, the SkyTrain and Canada Line systems are grade-separated — mostly elevated, with some underground sections. The obvious advantage to that is the ability to bypass traffic altogether, run at fairly high speeds (up to 50 miles per hour or 80 kilometers an hour) and operate in all weather. The construction costs are variable, but considerable: approximately US $120 million per mile elevated; an average of $200 million per mile for an underground system, and about $100 million per mile for the Evergreen Line, which will be largely at grade.

SkyTrain’s automated mini-metro technology was considered the best for the Vancouver area, expandable to carry up to at least 25,000 people per hour in each direction. Peak hour ridership now exceeds 10,000 passengers per hour (peak link, peak direction), equivalent to four full freeway lanes. Growth is effectively capacity-constrained until delivery of 34 additional cars in 2009, which will provide an additional 22 percent capacity. While fully segregated busways can move up to 15,000 people an hour, mixed traffic operation limits capacity. Vancouver’s three rapid bus lines have limited street priority, including curbside bus lanes, some signal priority and carry a maximum of 2,000 people per hour per direction.

One of the advantages to SkyTrain has been its driverless technology. Personnel are free to patrol the system, responding to situations like helping visitors understand the system, managing crowds during peak periods and even driving the trains when needed (SkyTrain attendants are certified motormen).

The trains are controlled from a central facility where operators monitor real-time computer displays, showing information on all of the trains in service. They are able to take control of trains at any time, while being aware of the locations of all the other trains on the system at once.

TransLink decided on light-rail transit for the Evergreen Line for a variety of reasons. While much of the urban growth mentioned earlier has been to the east and southeast of the city, the rate of growth of Greater Vancouver’s Northeast sector has surprised many people. The topography of the region, which is mountainous in some areas, does not allow for widening of roads. Neither, in fact, does public sentiment. Light rail offers high capacity, and since it travels at grade rather than above ground, it’s more compatible with community objectives.

For light-rail transit to operate effectively, it needs segregation from other traffic and traffic signal priority. The Evergreen Line’s per-mile cost is actually quite high, but it includes the cost of boring a 1 ½-mile (2 kilometer) tunnel in a location where the grade is too steep to negotiate at the surface.

Trolley vs. Track
Greater Vancouver is a region with a variety of urban development, geographical challenges and even micro-climates. A snowy morning in Surrey could well have only drizzle in downtown Vancouver. This presents a variety of challenges for transportation planners, and what works in one area may not necessarily work in another. The transportation network developed by TransLink over the years incorporates a variety of transportation systems that work for those particular areas.

Trolley buses have proven to be energy-efficient, reliable workhorses in the high-density downtown and along built up north-south urban arterials in the city. While trolley routes are not as flexible as routes served by diesels, they do convey a sense of permanence in the community.

Trolley buses do require a large up-front investment in overhead and the buses themselves. However, both investments will last a long time. Electric trolleys are definitely quieter than diesels and are emission-free; if the electricity is generated by environmentally friendly means, that’s an added bonus. We note the ongoing debate as to whether hydroelectricity is, in fact, green. BC Hydro, with the GPCs we mentioned above, does consider hydroelectricity to be brown power. Nonetheless, if a city has a large enough population and has essentially reached the end of its urban sprawl, a trolley system can be a popular route to go in these environmentally sensitive times.

SkyTrain has enabled expansion of the region eastward, allowing the development of a number of higher density sub-centers and promoting two-way traffic along the lines. The grade separation allows the train to ride over the traffic, while the centralized operations system allows for greater control over all the trains and more efficient responses to situations. Like the trolley bus system, it requires major expenditure up-front, but once built, can be counted on to last a long time. The original SkyTrain vehicles, which went into service in 1986, are still in use and are only now considered to be at mid-life. Here again, the anticipated volume of ridership both currently and over the next few decades would have to justify that expenditure. We have also found that public relations reminders are needed, pointing out the efficiency, fuel savings, reduced traffic congestion and amount of greenhouse gas not being produced by private vehicles. As with subways and true bus rapid transit systems, the speed of the commute is another major selling point.

A light-rail transit system requires less up-front investment in trackage and stations, but also requires dedicated lanes and traffic signal priority systems to be in place, to allow the trains to get around traffic. Here, too, the selling points are less about speed of the commute and more about the advantage of moving a large number of people at once and the resulting reduction in traffic congestion.

Drew Snider is a media relations consultant for TransLink in Vancouver, B.C.

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