Civil Engineering Reference
In-Depth Information
spaces provided to serve speci
c land use activities. Thus the provision of large
amounts of parking at major suburban traf
c generators concentrates traf
c demand
which creates traf
c congestion. There is, however, a growing emphasis on
adopting parking reforms and developing land use sites and design that foster
shared parking, ridesharing and/or transit use. For example, up to two thirds of the
parking space serving of
ce buildings is empty in the evening peak hour.
Accordingly, attitudes toward providing suburban parking are beginning to
change. Minimum parking requirements sometimes have produced an oversupply
of parking spaces and are a disincentive for ridesharing, transit, or other commute
alternatives work in the suburbs [
10
].
A few communities have reduced their parking requirements when they initiated
as part of ridesharing or TSM programs [
11
]. Examples include Palo Alto, CA;
Orlando and St Petersburg, FL; Montgomery County, MD; and Bellevue Wash-
ington. But these actions have been not been signi
cantly replicated elsewhere.
22.3 Park-and-Ride
Limiting and managing downtown parking supply can effectively reduce traf
c
demands and traffic congestion when complemented with remote park-and-ride
facilities along express transit lines. This strategy helps to keep downtown parking
and traf
c demands constant
—
even as the downtown employment grows.
It reduces commuter traf
c volumes on heavily traveled and often congested
radial freeways and arterial roads
It enables city center employment to grow without corresponding increases in
downtown street congestion
It builds transit ridership for downtown destinations from travelers that live in
low density areas (where transit is not sustainable)
It permits wider station spacing on express transit lines in outlying areas where
there is usually little walk access to transit station
Remote parking facilities (
“
park- and-ride
”
and
“
park-and-pool
”
) provide a means
of accommodating future central area transit demands
especially where downtown
parking space is stabilized. They take the form of park-and-ride facilities at express
transit stops, and park-and-pool facilities where transit service is limited. They range
in size from a few hundred spaces at outlying park and pool lots to large multistoried
garages serving commuter rail and rapid transit riders. In effect the downtown com-
muter parking demands are transferred to outlying locations. This parking intercept
strategy, shown in Fig.
22.2
, has several advantages in reducing congestion [
5
].
The number of park
-
and
-
ride travelers multiplied by their trip lengths on the
train, bus or carpool, is a measure of the VMT removed from the roadways and, in
turn, of reduced traf
—
c congestion on these same roads.
These savings are balanced
versus the additional traf
c concentrated on roads used to reach the car-and-ride/
pool facilities.
