Lec 10, Ch.4, pp.121-127: Parking studies (objectives)

Understand parking planning is an integral part of transportation planning

Know the definition of parking terms Learn the methodology of parking

studies Learn how to find out space

requirements for a parking garage

What we cover today in class…

Why do we need to conduct parking studies

Types of parking facilities Definition of terms related to

parking studies Steps of parking studies Steps of analyzing parking data

Parking needs

Types of parking facilities

On-street parking facilities:

Off-street parking facilities:

Private vs. Public

Surface lots vs. garages

Self-parking vs. attendant-parking

Parking bays alongside the curb

Question: What kind of parking do we have in downtown Provo?

Definitions of parking terms

Space-hour A unit of parking defining the use of a single parking space for a period of 1 hr.

Parking volume

The total number of vehicles that park in a study area during specific length of time (usually a day)

Parking accumulation

The number of parked vehicles in a study are at any specified time.

Parking load The area under the accumulation curve between two specific times. (space-hours)

Parking duration

The length of time a vehicle is parked at a parking bay.

Parking turnover

The rate of use of a parking space. Divide the parking volume for a specified period by the number of parking spaces.

Four steps of parking studies

1. Inventory of existing parking facilities

2. Collection of data on parking accumulation, parking turnover, and parking duration

3. Identification of parking generators4. Collection of information on parking

demand

Info included in parking studies

Parker characteristics (when, where, why and how many people park)

Parking supply characteristics (number, location and cost of spaces, who provides and how spaces are controlled and used)

Parking needs for new or existing developments

Demand Factors Changes in population, motor vehicle

registrations, and travel Changes in CBD employment, floor space, new

economic activity generators and loss of existing generators, competition from outlying areas

Economic factors relating to a specific parking project (competitive price changes, subsidies, development of competitive parking facilities)

Change in public transit availability, service and usage, or other changes in CBD accessibility

Public policies regarding parking and transit Technology or science affecting transportation,

new laws and regulations affecting motor travel, energy or fuel shortages, and community and national economic health

Inventory of existing parking facilities

Type and number of parking spaces Times of operation and limit on duration

of parking Type of ownership Parking fees Restrictions on use Other restrictions (near bus stop, fire

hydrant) Probable degree of permanency

Collection of parking data

Accumulation – checked about every 2-hr basis

Turnover and (max permissible) durationT = (No. of different vehicles parked)/

(No. of parking spaces)

Time of day

No.

of

park

ed

ca

rs

Demand fluctuates.

Identification of parking generators

Spacial distribution, size of parking generators (trip attraction facilities), and available transportation modes affect the level of parking demand.

Parking demand survey

Interview drivers on a typical weekday between 8:00 am and 10:00 pm.

Or, give drivers a survey form

Trip origin

Trip purpose

Destination after parking

Arrival and departure

Vehicle type

If you get 30% back, you are really fortunate.

Analysis of parking data

No. and duration for vehicles legally parked

No. and duration for vehicles illegally parked

Space-hours of demand for parking

Supply of parking facilities

Parking demand estimation

N

iiitnD

1

D = space vehicle-hours demand for a specific period of time (usually the duration the parking

facility is open)

N = number of classes of parking duration ranges (commuters, shoppers, business meetings, etc.“Class” means grouping of purpose and parking durations)

ti = midparking (meaning “average” here) duration of the i-th class.

ni = number of vehicles parked for the i-th duration range (meaning “class”)

ClassN (= 2 here)

Average durationti

No. of vehiclesni

Commuter 9 hrs 120

Shopper 2 hrs 80

Parking supply estimation

M

jjtfS

1

S = practical number of space-hours of supply for a specific period of time

M = number of parking spaces available

tj = total length of time in hours when the j-th space can be legally parked on during the specific period

f = efficiency factor to take into account the time lost during turnovers

Simply stated: S = f*tave/space*M

j = 1, 2, 3,…

10hrs