Transcript the case against wheel stops and curbs

The Twilight Zone
TPTA Roundtable
July 23, 2012
Video Evidence
Distribution of Liability Claims
(Percentage of claims paid by US parking operator)
Gate Injury
5%
Probably doesn’t
include fender
benders; most paid
by auto insurance.
These are mostly
valet damage
claims.
Other
7%
Vehicle
Damage
9%
Assault
6%
Slip & Fall
57%
Trip & Fall
16%
Nearly ¾!
Data from claims to a national parking operator over four months,
Source: Monahan, Donald R “Safety Considerations in Parking Facilities”
The Parking Professional, September 1995
Pre-collision Actions
(Percent of incidents)
One vehicle parking
Parking and unparking
comprise 2/3!
One vehicle cutting across parking rows
Head-on or Rear end
Sideswipe
Both vehicles unparking
At aisle intersections
One vehicle unparking
0
10
20
Box, Paul, “Parking Lot Accident Characteristics”
ITE Journal Dec 1981
30
40
50
More info from Box Article
Accidents reported to Naperville IL Police
•Data base of 825 accidents over three years (1978-80) in
facilities with 15,850 parking spaces.
•24 accidents with injuries (3%)
•Moving vehicles striking moving vehicles comprised 29% of all
accidents, but just over half (13/24) of accidents with injury
•Of 24 accidents with injury:
•
•
•
•
•
•
•
6 occurred at aisle intersections
5 veh hit pedestrian (0.6% of all accidents, 21% of those with injuries)
5 occurred when moving vehicle struck fixed object (1 was a curb!)
3 one vehicle cut across parking rows
2 vehicle backed out of stall into path of other
2 sideswipe (both vehicles driving forward)
1 vehicle driving down aisle struck parked vehicle
Collision Involvement in Parking Facilities
Collisions in parking facilities
(Percent of incidents)
Vehicle-Cyclist
0.5%
Vehicle-Pedestrian
3.5%
Very similar
to Box study;
accounts for
20% of
injuries
Vehicle-Vehicle
96.0%
1996 Data
Source: Safety Design Guidelines in Parking Facilities, First edition,
Vancouver: Insurance Corporation of British Columbia, Sept 1998
Benefit of Liability Claims Data
Even if lawsuits are not a direct concern
(e.g. in less litigious countries)
the data shows
WHAT CAUSES SERIOUS INJURIES in parking facilities
Fix the Lighting!
Lighting Uniformity
Avoiding the #1 Claim
ASTM Standard F1637 Safe Pedestrian
Walking Surfaces, Summary:
• Illuminance per IESNA (latest edition)
• Walking surfaces shall be slip resistant, including pavement
markings where wet conditions reasonably anticipated.
• Changes in level: same as in ADAAG (even where not an
accessible route)
• ¼” max vertical edge, beveled ¼ to ½”, No edges >1/2”
• Avoid wheel stops; where necessary, center in stall, min 3’
clear between ends (for 8’6” stall, that mean 5’6” max long)
• Avoid speed bumps
• IBC prohibits speed bumps in parking facilities
• If required, use speed humps, paint (with slip resistance) and
add pedestrian warning signs
In addition to ASTM IBC, and ADAAG stds,
most consultants recommend:
• Wherever possible, use following to direct/control traffic* or
separate vehicles from peds:
• Bollards
• Pipe guards
• Flexible delineators
• Provide curbs/wheel stops only where no alternative to
protect
•
•
•
•
Buildings
Landscaping (surface lots, green roofs etc)
Connections (precast spandrel panels)
Equipment
• If pedestrians might conceivably cross a necessary curb, paint
yellow on vertical face and 6” horizontal
• Not needed at perimeter where peds wouldn’t typically go across curb
*Including preventing vehicles driving across parking lots….
Slippery Floor Surfaces
• 57% of claims from slip and fall.
• Various floor surfaces (concrete, asphalt, coatings, snow, ice, water).
• Current codes (including ADA, IBC and OSHA) do not have a required
minimum for coefficient of friction and/or slip resistance.

Recommendations are provided, but no recognized testing method is available.
• Proper drainage, even where covered and rain is rare
• Traffic toppings/coatings loose their abrasion resistance (sand) over time
and must be recoated.
• Stair treads have little surface area for foot and need to be slip resistant.
Consider adding abrasive nosings, if necessary.
• Use glass beads or sand at large painted floor markings (turn arrows, stop
bars, etc).
Curbs of any type CAUSE INJURIES
and should be avoided in parking.
• More liability claims in US for slips/trips and falls in parking than any other
issue; 73% of claims in one study
• People are more likely to be injured by trips/slips and falls than by fender
benders from people driving across parking lots.
• New ASTM standard (2002, reissued in 2009) for safe walking surfaces
recommends against wheel stops and curbs
• It was “on radar” of ASTM to do requirements for parking areas!
• Even though not (yet) incorporated by reference in building codes,
ASTM standard will be used by plaintiffs in lawsuits.
• Wheel stops also make it difficult to clean parking areas, collect refuse, etc.
• Wheel stops are not effective at assisting drivers to park properly in stalls.
• Wheel stops are difficult to secure, and damage the concrete over time.
Curbs/wheel stops can be trip hazards
Wheel stops in this position are even
more likely to result in trips and falls
than when stop is centered in stall
More importantly note how difficult it is
to see wheel stop when concrete on
concrete.
Unpainted wheel stops used, offcentered. While some curbs beyond are
painted, they still can cause trip hazards
Curb intended “to protect” elevator waiting area, added
railings (reportedly) after trip and fall
Bollards
instead of
curbs
would be
better!
Use bollards to separate pedestrians
from vehicles instead of curbs
We don’t need curbs here, either!
Use paint, bollards and pipe guards to direct
traffic; use curbs only where necessary
No curb between
traffic flow in
opposite directions
on ramps (except
where required to
prohibit turns)
No curb on ramp
edge; yellowpainted, concretefilled post protects
pipe
Note: equipment islands are absolute
minimum required, with extra posts for
further protection of equipment. Curb is
for setting equipment
Paint necessary curbs yellow where peds might
conceivably cross in path to/from destination
Curbs at tower
painted traffic yellow
Wheel stops didn’t
protect these signs!
Instead of wheel stops,
put accessible sign in
concrete-filled steel
post, painted traffic
yellow, centered on
stall, out of ped path.
Note difficulty seeing wheel stops away
from light fixtures on asphalt too
Where curbs required, hold curbs back 10” min,
12” preferred, from nominal stall line
Minimizes risk of
somebody stepping
out of car onto curb
or tripping over it.
Also gives same
comfort of turning
movement into stall
as other stalls.
More info against wheel stops and curbs
• If concerned about “cross country” driving, break into smaller sections with
long islands, heavily landscaped to help pedestrians realize it is not a ped
path.
• Use islands instead of wheel stops because difficult and expensive to clean
behind wheel stops. Mechanical sweepers and/or snow removal equipment
cannot access. Significant because regular maintenance and cleaning of
floor areas are critical to durability.
• Curbs are NOT adequate to control lot perimeters for revenue control
• Curbs are NOT adequate to meet code required vehicular impact loads
• None of the usual connection methods of wheelstops are desirable. Stops
epoxied to floor may be knocked loose often taking some surface with it. If
the wheel stop is bolted or otherwise mechanically anchored, even small
but repeated impact loadings can damage paving around anchor.
• Creates path for water penetration into concrete (and corrosion) or into
base under asphalt.
• Damaged surface can also be an additional tripping hazard
Wheel stops do not significantly improve parking
position in stalls
•Low profile vehicles stop short.
•If placed far enough to protect element from maximum
vehicular overhang, cause vast majority of cars (which have
less overhang) to park farther out towards aisle.
•Useless for “Texas style” parking.
•If knocked loose, causes yet more problems parking in stalls
Therefore wheel stops and curbs have more negative than
positive benefits.
Therefore:
•Provide curbs ONLY where required to protect:
• Landscaping
• Vulnerable construction
• Structural connections (e.g. spandrel panels above grade)
•Where required for above, and where pedestrians might
foreseeable (wisely or not) try to walk across, paint vertical
face and 6” at edge along top TRAFFIC YELLOW
•Eliminate wheelstops
•Lighting to meet IESNA (latest edition)
• Calculate illumination at END of rated bulb life
 Most owners don’t relamp until burn out