Civil Engineering Reference
In-Depth Information
population is usually located within a quarter mile of a transit stop, transit
'
s service
area of the urban area
'
is employment is smaller. Thus if 90 % of an area
'
s popu-
lation is served by transit, and 50 % of an area
'
is employment is served by transit,
this combines in 45 % coverage
resulting in fewer potential transit trips.
Increased transit coverage can be achieved by (1) modifying existing routes, (2)
providing better pedestrian access to stops, and (3) locating future commercial
developments near transit stops.
—
23.4.2 More Frequent Service
—
Bus service frequencies depend on transit demand
longer headways are found
where demand is low, while short headways predominate when demand is high.
Whenever practical, headways should be shorter than riding time. Where transit
service frequency is less than 10
-
12 min, passengers arrive at transit stops at
random, while longer headways require passengers to refer to schedules.
23.4.3 Route and Service Improvements
Transit routes and services are normally governed by transit agency policies and
standards. Good operating practice follows these guidelines:
There generally should be one route per arterial street. However, there can be
more routes where streets and bus lines converge as they approach city centers.
There also can be more services on a street where local, express, limited stop
and bus rapid transit services run on the same street
Fewer routes with shorter headways are preferable to many routes with long
headways
—
operating on the same street.
Excessively long routes can result in
“
bunching.
”
Therefore, routes longer than
about 1.5 h each way should be avoided
Routes
through
the city center are preferred to looping routes. Looping routes
can result in more turning movements and traf
icts. However, looped
routes can be necessary where (1) ridership on each leg is not balanced, (2) the
through routes would be too long, and (3) additional coverage is needed.
c con
fl
Bus terminals are sometimes provided in city centers. They generally are
desirable to serve long distance and low-frequency local services.
23.4.3.1 Reducing Delay from Transit Stops
The number of stops and the duration at transit stops should be minimized. This is
because each stop delays transit vehicles, and sometimes motorists following buses
or street cars. Time is also lost accelerating and decelerating to and from stops. Bus
