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Change of Mode Parking
The following excerpts were taken from the1992 edition of the Transportation
Planning Handbook, published by the Institute of Transportation Engineers (pp.
183-184).
. . . There are two general types of park and ride lots: (1) a change from the private
vehicle to some form of public transportation such as bus, rapid transit, or suburban rail
and (2) carpooling.
Transit Stations
The interfaces are the following:
- Pedestrian or walk-in-traffic
- Private automobile park-and-ride or pickup/drop-off
- Transit transfers such as bus to bus, or bus to rail
- Taxi
For most locations, there are two elements to the park-and-ride function: (1)
long-term, all day commuter parking, which represents the major consideration, and (2)
short-term spaces that are desirable to encourage midday shopper, sporting event, or other
personal trip usage of the transit facility during off peak periods. These spaces would
typically be used from 4 to 6 hours. Efficiency of land use is enhanced by combining the
P/D operation with the short-term space needs. Thus, a very short time limit during the
A.M. and P.M. peak transit activity, such as 5 to 10 minutes, is imposed on a limited
number of spaces adjacent to the station. These spaces are then available for
intermediate-term parking during the balance of the day. The major P/D problem involves
the pickup element in the evening, when motorists arrive and temporarily park while
awaiting arrival of the commuter train or express bus. . . .Additional planning elements
of the transit terminal include loading/unloading spaces for buses and waiting areas for
taxis.
The important parking characteristics of a transit station include the number of P/D
spaces needed versus the number of long-term spaces. Reliable estimators for the number of
P/D spaces, on a per-originating-daily-passenger basis, are needed but have not been
identified. Three studies in the Chicago area found a range of 0.05 to 0.07 (average 0.06)
spaces per originating passenger; however, additional research on this parking demand is
needed in other cities. . . .
The parking space demand per originating passenger at various types of terminals is
given in Table 6.9 (not included here) and suggests a need of about one space per
three passengers. The Chicago area developed a method of estimating current and future
parking demand at each station, using data from ticket sales by mail:
- Determine the natural service area (NSA) by geographic zones having boundaries defined
by existing patterns of user origins and expected future development.
- Calculate the current NSA.
- Calculate the current NSA parking demand.
- Project ridership growth.
- Determine the future NSA.
Fringe Parking
Change-of-mode parking facilities can be located at the outer edges of the CBD, or at
more remote distances. Those located near CBDs are served by local or special shuttle
buses. Those located farther away are typically served by express buses, rapid transit,
and/or suburban rail. An ITE committee found that bus-serviced lots have the greatest
usage close to the CBD, with a smaller peak at the 11- to 13- mile range. Rail lots have
the greatest usage in the range from 5 to 15 miles from the CBD. Most bus-serviced lots
have transit times greater than automobile travel times, whereas those with rail typically
have shorter travel times. Most change-of-mode lots have transit service for 14 or more
hours per day, and peak-hour transit service headways of 25 minutes or less. In the
Cleveland fringe, buses were reported operating with 5-minute headways during the peak
hours.
Locational factors for parking facilities were identified by Ellis, Bennett, and
Rassam:
- Fringe parking facilities should be located in transportation corridors so that they
intercept home to work trips destined to the CBD at a point where there is sufficient
density of traffic demand that high-quality transit service may be offered.
- To the extent feasible, facilities should be located on land that is already used for
parking or in low-grade nonresidential use.
- Such facilities should be located on sites compatible with land uses and activities in
the immediately adjacent area.
- Potential joint-use aspects of a facility should be considered.
- Trade-offs in the scale of the facility (such as the level of transit service as opposed
to its neighborhood impacts and the ease of access) should be considered.
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