This article is the first in a series of articles about how bus routes and schedules get planned, from the initial determination of the route to ongoing maintenance of the schedule. Practices mentioned in the articles are ones that I engage in on a daily basis that I have found to be useful in my twenty-eight years of studying and following transit systems. TCRP Report 100 , put out by the federal government, is essential reading on this subject.
Part I: Placement of the Bus Route
A. Route In New Area
As you can well imagine, proper route placement is the key to success of a given bus line. Before you begin the route creation process it is essential to have a complete understanding of the existing route structure and demographic makeup of the service area for your new route. Many transit systems have service standards which dictate that a certain percentage of the service area's population and employment be a certain distance from the nearest bus stop, usually 1/4 mile. Referring to your system's service standards in conjunction with demographic and employment data available from the United State Census Bureau and other sources, check to see if appropriate network coverage is currently provided. OC Transpo of Ottawa, Ontario endeavors to ensure that 95% of the Ottawa population lives within 1/4 mile of a bus route. While there are likely to be certain parts of the service area that are without transit coverage, before new routes are operated in these areas demographic data must be consulted to make sure sufficient density exists to support service. For example, the Denver, Colorado RTD service standards mandate regular service for areas that have 12 or more residents and jobs per acre.
Once you identify an area that needs new transit service, the first thing you should do is determine the terminus locations. Route termini need to, as much as possible, be significant trip generators. Examples include downtown areas, hospitals, universities, malls, and transfer centers. Sometimes the demographic data referenced above can identify areas that have robust housing or employment but are not obvious trip generators. At least one end of the route should have adequate layover facilities, including access to at least restrooms for the operators, and preferably refreshment opportunities. Not providing sufficient amenities at the end of the route will likely cause operators to stop at a mid-route bus stop to use restrooms and access refreshments. Of course, route termini that are on private property will need the approval of the property owner, which may be difficult to obtain.
Once the two terminus locations are identified, selection of the route follows. As much as possible, the route should follow the shortest road distance between the two end points. Deviations to serve important trip generators are possible, but the ridership generated by the deviation should be a greater percentage of the overall ridership than the additional running time needed to serve the deviation is of the total running time. For example, if a route which has a running time of 60 minutes includes a deviation which takes 6 minutes of that time, then the total ridership generated by the deviation should be greater than 10% of the total.
Other factors that should be taken into account when designing the route include the presence of other routes nearby and the type of street the bus will travel upon. Except in very dense areas, parallel bus routes should be no closer than 1/2 mile to each other. The grid nature of most American street networks makes this condition easy to follow. In terms of the type of street that should be chosen, a pedestrian friendly mid-major street should be picked if available. Due to their politically sensitive nature side streets should be avoided, and major arterials with speeds of 45 mph or greater should also be avoided unless there is no other choice due to the problems with bus stop location and bus stop access. In addition, streets with traffic calming measures such as speed bumps, speed humps, or traffic circles should also be avoided. In many cases bus routes will have no choice but to traverse streets with some of the above conditions; thus, the judgment of the transit planner will have to come into play to make the best of a bad situation.