Civil Engineering Reference
In-Depth Information
Table 23.5 Transit modes related to residential density
Mode
<Minimum CBD employment
Rail rapid transit/commuter rail
100,000
Light rail/grade separated BRT
70,000
Express bus
35,000
50,000
-
Local bus
10 min service
20,000
25,000
-
30 min service
7,500
10,000
-
Source
Adapted from Reference [
4
]or[
8
]
Public transportation usage is higher in urban areas where:
There are high residential densities and a large downtown or other cluster of
non-residential activity
Residential developments are located in close proximity to non-residential
concentrations
Transit service is convenient, reliable, and frequent
Parking space is scarce and/or expensive
One set of guidelines [
8
] to assess the suitability of implementing rail rapid
transit, light rail transit, and bus rapid transit is provided in Table
23.5
.
23.3 Transit Improvements
23.3.1 Context
The importance of maintaining good transit for enhanced mobility
—
especially in
major cities
is increasingly recognized in the US where many transit systems have
been upgraded, and major new systems have been built. Bus rapid transit lines, used
for many years in major world cities have emerged in the US and light and heavy
rail lines have increased in number and extent. In addition, vehicle design has been
advanced as well (for example, some buses now have doors on both sides).
The following sections show how transit operational treatments can enhance
existing service, improve street system ef
—
ciency in moving people, reduce transit
travel times, increase service reliability and reduce operating costs. They also
describe the type of physical improvements that expand person capacity in major
transit corridors to make service faster and more reliable, and provide a framework
for achieving more compact land developments.
