Source : Grava, Sigurd 2003. “Trolleybuses.” Pp 421-436 in Urban Transportation Systems, (c) The McGraw-Hill Companies, Inc.
Reasons to Exercise Caution
Most operating agencies in North America do not particularly favour trolleybuses, which explains to a large extent these vehicles’ lack of prominence in the transit sector in this part of the world. The crux of the matter appears to be that most of the positive features resonate well with users and communities, who do not see the expense sheets, while the shortcomings directly affect the efficiency of agency operations, which is always under public scrutiny. The need for overhead wires is the principal drawback of trolleybus systems that generates most of the specific negative features. They represent a significant capital investment (particularly the copper wire itself, which wears out), and there are considerable engineering and construction efforts involved in keeping them on top of busy streets at an even and constant elevation.
Unsightliness is the most often cited problem in public evaluations of this mode, as expressed by the overhead wires. At a large intersection where several routes converge and make turns, the spiderweb above can be a structurally heavy and visually oppressive presence Even on simple straight runs there will be span and support cables, electric insulators, junction elements, poles and anchors, and feeder cables. On the other hand, perceptual surveys of city residents frequently indicate that people do not “see” the wires, i.e., they fade to the background in the total urban scene. Nevertheless, once alerted, most everybody will notice them and complain about violations of their aesthetic sensibilities. Some screening can be provided by trees, provided that they are properly trimmed to avoid contact. Feeder cables can be placed underground.
The vehicles are tied to the lines without much flexibility in selecting a path. Trolleybuses can usually drive around small obstacles, but this mobility is limited to the next lane on either side. Temporary diversion of a route to a different street (to repave or do major utility work) involves considerable effort and expense in moving and replacing the overhead wires.
The wires may be obstacles to other activities, such as vehicles with high loads, fire ladders, parades, etc. Running a route below structures with low clearances may also be a problem.
The power pickup shoes frequently lose contact since there is little to keep them in place except a groove and the pressure of a spring on the pole. The replacement can be done quickly enough, but it does require the driver to leave the seat and walk to the back to fit them back manually, thereby losing at least a few minutes in the schedule. Mechanical devices have been invented to do this job, but they do not appear to be worth the trouble in normal situations. Snow and ice under extreme weather conditions can interfere with power pickup arrangements. If the shoes are maintained properly, and switches and sharp turns are negotiated at reduced speed, problems should be minimal.
The purchase price of a trolleybus is high as compared to a regular bus. A few years ago, a 50 percent premium was not uncommon for a vehicle of the same capacity. Currently, the price of an electric trolleybus is $642,000 (a 40-foot regular transit bus sells for $295,000). This is certainly due to the limited market, since for all practical purposes every unit has to be individually made. With comparable production volumes, a trolleybus should cost the same as, if not less than, a regular bus.
Costly infrastructure has to be in place, which was not a large problem in the early days when streetcar power distribution systems (including overhead wires, poles, feeders, substations, etc.) could be readily adapted. It is, however, a major consideration if a new network has to be created. There is no reliable cost experience to go by because little has been built in the trolleybus sector for several decades in North America.