INTROdUCTION fundamentals types
A Case Study in User Behavior: Princeton University Parking Structure Drivers have fundamentally different experiences,
users begin to go home. Traffic levels are main-
especially in parking structures where there is a
tained as this exit pattern is balanced by an
mix of nearby program. At Princeton, there are a
entrance pattern of students. Also typically famil-
few basic groups of customers: faculty, staff, stu-
iar users, students make use of the bottom-to-top
dents, and visitors.
vacancies.
Faculty and staff are typically the biggest segment
Throughout any given day and for some special
of familiar visitors, arriving earliest in the day. At
occasions, the garage may be used by authorized
this point, vacancies are arranged top-to-borttom,
off-campus visitors: they are the unfamiliar oppor-
and are located mostly away from the pedestrian
tunists following the longer circulation pattern
circulation cores (which include the exits). Though
shown later in this section. For these users, way-
the garage is open around the clock, it is reserved
finding is critical. The Princeton garage is outfit-
between the hours of 8:00 am and 5:00 pm for
ted with directional arrows on the driving surface
university employees. During this period, the
as well as various columns at the corners and the
usage increases dramatically in the first couple
entrance and exits of the ramp. There are numer-
hours, then plateaus for the majority of the day,
ous floor-level indicators to help drivers remember
seeing some activity during the lunch hour. The
where their vehicle is parked, and also to direct
rate of vehicle movement increases as the end of
them to exits, stairs, and the elevator.
the business day approaches, and faculty/staff
SOURCES
PLANNING AND DESIGN
Project Data Location: Princeton University Engineering Quad, Princeton, NJ Dates of construction: 1988 - 1991 Architect: Machado & Silvetti Architect-of-record: Peter Longren Consultants: Lim Consultants, Inc. (structural); Cosentini Associates (mechanical); Van NoteHarvey Associates (site); Berg/Howland (lighting) Construction type: Steel frame w/ concrete deck Building Area: 165,080 GSF Number of stalls: 403 391 faculty/staff; 9 accessible; 3 reserved. 291 full-size (9’-0” x 19’-0”) 112 compact (7’-8½” x 16’-6”) Parking stall-area ratio: 38.7% (64,006 SF) Area/stall: 410 SF Ramp-area ratio: 7.8% (12,895 SF) Drive aisle-area ratio: 34.8% (57,500 SF)
Locating exit-access is a component of the user experience that affects where drivers will eventually park: they may even go to the next level of the garage in order to find a vacant stall adjacent to a pedestrian exit. In addition, the no-charge operation of the facility provides some alleviation to high volume periods of use because there is no delay for taking a ticket or making a payment. This allows vehicles to enter the circulation path immediately, which is a measure of efficiency; however, because of this, there is a potential for conflict with vehicles that are recirculating on the ground floor.
Top: View of garage exterior Middle: View of ramp system. This image illustrates one possible negative factor for users: a dim, foreboding interior that does not evoke a feeling of security. Bottom: Typical parking deck. In addition to a feeling of relative lack of safety and overhead clearance, this view shows another negative factor for drivers: a bright exterior view at the end of a much darker drive aisle. This is distracting at the least, and can cause safety issues.