Light Rail vs. Trolley Bus

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.