Civil Engineering Reference
In-Depth Information
Fig. 11.2 Hierarchical versus well-connected road networks.
Source
Reference [
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]
walking or biking than it is to driving. Thus the importance of providing network
connectivity that allows walking and biking for
short trips
becomes a key factor in
determining the accessibility potentially provided by these modes.
11.2 Measuring Accessibility
Accessibility of activity sites can be measured for a variety of conditions. For
example: (1) from one
s home location
to a number and size of activity sites
(employment locations, retail and service outlets, or recreational opportunities), and
their size, that can be reached at a given time from the person
'
'
s home; (2) from a
store location
to potential customers; or (3) from a particular location (e.g., the
Central Business District) to residential zone.
The number of activity sites that can be reached is determined by how much time
one is willing to spend on the trip, and the speed of the mode used. The mode
chosen for the trip also depends on the travel
options available
and their level of
service. In addition to speed, other factors considered in mode choice are trip cost,
frequency, reliability, comfort, convenience, security, etc., and availability of space
for vehicle parking (if needed).
The travel time needed to arrive at a chosen location is the product of the door-
to-door speed of the travel mode and the travel distance.
11.2.1 Examples
Several examples illustrate how accessibility can be determined are provided below.
