This space will be utilized to update participants of the New Tools for Parking Design and Analysis
webinar October 25, 2011 of the questions they had at the webinar that were answered in the last 30 minutes. Five questions were not answered and will be addressed here as will the all the questions - they will be attached. Should participants have further questions, we can address them here.
One clarification - subtle - on the webinar quiz question #1: Design of traffic control for circulation in parking areas requires: a) an architect, b) an engineer, c) a city code, d) the MUTCD, e) the owner
Note that the reference to "circulation" here is to roadways in parking areas - it may be better worded "...circulation on parking area roadways
Here is the question and answer material - add comments if you have further questions and I will periodically update via comments.
October 25, 2011 Parking
Webinar Q & A Questions
Comment: In addition to your Huntington Beach city hall example, FedEx
Field Football Stadium in Maryland just installed those solar car ports.
Q: Do you have any guidance on parking to prevent vehicle intrusion
A: When no curb is provided with disabled person
parking spaces, the sign that restricts spaces can be placed on a durable pole
or bollard – however, this has not emerged as a major issue.
Q: My limited experience, it seems like high LOS can equate with
A: Two way can provide more flexibility for access. One-way can confuses/frustrate some people
and force trips to the front of buildings where more pedestrian conflicts are
possible. Angled parking and 1-way operation
can be used to fit parking into odd spaces.
It is a site by site specific consideration
Q: Please define cross-aisles and design characteristics
slide 21 on your PPT copy for an example
Q: Is there a standard related to length of gate arms at parkade
aware of that. It is important to
consider pedestrian exit (emergency or otherwise) to have space that is not
fully blocked (also bike), but the gate needs to be effective in its access
restriction task for motor vehicles.
Q: Can we get a copy of presentation including the one with effects?
A: You may download the PDF copy from www.ite.org/education/parking/ The actual .PPT not allowed due to copyright
Q: Are any cities using the ITE Parking Generation Manual to
determine site parking needs instead of standard codes of number of spaces per
A: First – Parking Generation is an Informational Report NOT a
Manual. Many agencies utilize Parking
Generation as a tool in setting their code.
I am not aware of a city creating a nexus between the code and the data
in Parking Generation. Frankly,
eliminating minimum parking codes and requiring the parking to be an element of
site plan impact review may be a better approach to balance provision with
need, while identifying possible impacts of intrusion as a site approval
criteria (using Parking Generation for the demand analysis).
Q: Are there any recommendations or best practices for parking that
is provided to the side or rear of buildings?
Our city code prevents most parking in front of retail buildings, but
developers are often hesitant to comply
A: Must follow your codes and how restrictive they are. There are lots
of cases where parking is provided in front of buildings and you have to look
specifically at your codes/vehicle requirements/emergency service provider
preference (emphasis on the term preference).
Q: How do you display handicap vacancies in your parking garages
with a display?
A: Many garages do not address this. At the Portland, OR Airport, their advance
parking guidance system has LED signs above aisles with blue display numbers
for disable person parking space availability.
Very possible to accommodate that in other settings.
Q: Are there any recommendations regarding the use of compact
A: Look at your building codes. Good example of compact is the use of
compact stalls by the perimeter for peak parking , retaining standard stalls
closer to the building for routine use.
You have to look at your specific case in context. Many designers (and users) prefer single
Q: Is your presentation available to us to download?
A: Download the PDF copy from www.ite.org/education/parking/
Q: How successful has parking space banking been?
A: This has been used for sites that want the flexibility to add
parking the future should conditions change (flex industrial building being
used more as an office in a complying zone).
Q: What about the maximum grade in an interior parking?
A: Commonly garage parking
areas are nearly flat. Ramps can reach
15% as a typical maximum but these would not allow parking. Sloped floor garages that allow parking on
the slope ramps – typically ADA issues control in setting slopes not greater
than 5% (above that door openings can be difficult – some are 5.5-6%).
Q: Can you please describe some of the best practices for express
ramp gradients within parking structures, including slope transitions.
A: Take grades you have and divide by 2 and blend in 12-20 foot area
approach the full ramp slope.
Q: Are there any recommendations with regards to alternatives to
impervious parking lots? A: A: Lots of creative ideas out there today from pavers with large
gaps, to use of plastics with gravel to porous pavement treatments
Q: Are Portland's minimum and maximum ratios used everywhere outside
A: Many surrounding cities adopted the Metro guidelines in their
codes as part of Transportation System Plan updates.
Q: On page 12, Layout slide, it shows 340 - 450 sq ft per space yet
you stated 350 as the upper limit - which is correct?
A: The condition of 450 SF
per space is for conditions where the parking is under a building with lots of
columns penetrating the parking space.
The 350 SF per space is typical of an open layout for parking (surface
lot or clear span structure).
Q: We are working in a jurisdiction taking a comprehensive look at
re-doing our parking code. We are
referencing similar jurisdictions as well as ITE and ULI publications. What should we be careful with in reference
to the "averages" and "85th percentile" parking rates
created in the ITE Handbook?
A: This is a situation that requires
context. The average data might have
relevance as a good minimum parking and the 85th percentile a good
reference for maximum parking. It really
depends upon community interests – if parking intrusion is intolerable the
higher levels are often important. Where
water quality, transportation demand management and land use are valued, the
average number with justification for greater parking is an option.
Q: Really should mention automated parking that is a growing option
in urban areas
A: Robotic parking facilities have been around
for decades and achieved little traction – primarily due to cost, operational
issues and technology. Today robotics
are advanced enough, but cost and public perception can be issues. Hoboken, NJ has an example of this application.
Q: When looking at park and ride or park and bike lots, what other
considerations need to be taken into account other than sidewalks or bike
lanes? when there is no main building destination
A: Providing for bicycle access to transit platforms (bike lanes
or cycle tracks or trails) are always good considerations. The most significant issues are where trail
heads require access of a site to connect to the public ROW – in these cases
the parking areas need to consider appropriate treatments for bicycles to
Q: What should the color of pavement markings be in parking lots?
A: Color subject of debate. MUTCD requires white for on-street
parking. Some sites utilize yellow. Others use unusual colors to designate
employee parking from customer parking. I would commonly encourage the use of white.
Q: Although pedestrians prefer to use the shortest path, please
discuss barriers to redirect pedestrian activity.
A: I am a huge fan of planning for pedestrian
desire lines at the concept design level to address pedestrians needs as
efficiently as possible and avoid the need for barriers entirely.
Q: Is it unwise to mix angle and 90 degree parking in the same
A: In the same row this was called the Drachman method - in general
best practice would not include such a mix but if you are trying to squeeze out
an extra parking then there are circumstances you could. Keep in mind the aisle width should be design
properly and issues of sight distance to address potential two-way use of the
90 degree half of the parking as compared to the angle part is important.
Q: What is the enforcement authority for signing and markings on
A: For the roadways of private sites that use traffic control
devices, the MUTCD should be reviewed.
There really is no enforcement authority beyond the site plan review process
and potential for tort law to influence proper design.
Q: For bike parking and access cards, does that cause a trust factor
(someone with access card has access to everyone’s bike) is an attendant
necessary in these situations?
A: State of the industry access cards allow the access to the bicycle
enclosure/corral to be limited to the approved bicycle users – they can be uniquely
identified. Having an attendant is not
necessary (but if the economy stays in a funk, maybe that is a jobs
program). I park my bicycle in a garage
where the spaces are located near the cashier attendant – I feel that adds some
security since they are present in the vicinity during the day – for design
this is a good place to have bicycle spaces located.
Q: What are the parking design implications for electric vehicles
A: Examples are solar carports similar to those
noted earlier – these can use the solar power for the lighting and/or
recharging. In garages having spaces
with recharge kiosks can be considered – there is little demand today and
pricing of the charge is not well established presently. Sacramento has downtown garage spaces with
charging stations built in from the 1990s deployment of the EV1 – and now are
available for today’s EVs.
Q: what would you classify as a service aisle do you have a design
A: Aisle are the maneuvering area for vehicles between or adjacent to
rows of parking spaces. The widths of
aisles are variable with the angle of parking – NPA’s Dimensions of Parking provides
the best reference for this – 90 degree aisle are commonly 24-26 feet
wide. If this question was aimed at
defined the width of a parking aisle to allow service vehicles to access
loading docks – this requires turn templates to define the design vehicle needs
– commonly a wider aisle and more generous turn radius.
Q: Is there a particular reference for parking lot layouts for fast
food/drive in establishments?
A: Parking layout is no different but the drive
thru requires special consideration – McDonalds has corporate design criteria.
Q: Are there recommendations as to the location of public transit
facilities in large parking lots, such as regional shopping centers?
A: The fundamental here is getting transit patrons
as close to their destinations as possible with the least motor vehicle conflicts.
Minimizing the bus transit travel on site
is a good goal – for efficiency of the bus operation and the need for stronger pavement