Walkin in L'A'

1
Walkin in L.A.
Los Angeles Crosswalk Safety Study
Presented to WASHTO-X Peer Exchange Seminar

• By Rock Miller, PE

2
Study Purposes

• Validate Results of Previous Studies
• Verify Crosswalk Marking Practices

• Assist Los Angeles in Defense of Crosswalk
  Related Litigation
• Evaluate Safety in Uncontrolled Marked Crosswalks

3
Some Relevant Studies

• FHWA/UNC Study Safety Effects of Marked
  Uncontrolled Crosswalks, 2000
• KOA Santa Ana Citywide Crosswalk Study, 1997
• City of San Diego, 1970

4
Key Conclusions
San Diego
Crosswalks Generally Increase Risks
FHWA/UNC
Crosswalks Pose No Added Risk at Low-to-moderate
Traffic Volumes
High Pedestrian Volumes Reduce Risks
KOA/Santa Ana
5
Our Key Conclusions

• High Pedestrian Usage Is Strong Justification for
  Markings
• FHWA/UNC Study Recommendations May Not Adequately
  Consider Effect of High Pedestrian Volume
• Los Angeles Practice to Retain Crosswalks With
  High Pedestrian Usage Is Affirmed by Safety
  Analysis

6
Study Scope

• Marked Uncontrolled Crosswalks

• No Traffic Signals
• No Stop Signals
• Traffic Must Yield to Pedestrians

7
Study Data

• 50 Marked Crosswalk Sites
• Randomly Identified
• All on Multi-lane High Traffic Volume Roadways
• Various Neighborhoods, Ethnicity, and Income
  Levels
• Historical Traffic Volumes
• Offset Tee Intersections

8
Site Inventory Elements

• Traffic Volume
• Pedestrian Crossing Volume

• In / Out of Crosswalk
• Road Cross Section
• Marking Techniques and Treatments
• Significant Land Uses
• 8.5 Year Accident History

9
Probability of Accident

• 38 of 50 Locations (75) Experienced at Least One
  Pedestrian Crossing Accident
• In 8.5 Years, an Accident Will Probably Happen
• 0.2 Accidents Per Year Per Location
• A Request to Produce Records Will Likely Reveal
  at Least One Accident

10
All Sites Together

• 3.4 Billion Vehicles in 8.5 Years
• 120 Pedestrian Accidents in 8.5 Years
• One Accident Per 28.3 Million Vehicles

11
Compare to Other Studies

• 1 28.5 Million Vehicles

1 30 Million Vehicles
Starting to Look Like a Trend!
12
Typical Application

• 25,000 ADT

x 5 years
x 350 eq. Days/Year
43.7 Million Vehicles

• _at_ 1 Per 30 Million Expect 1.5 Accidents

13
Variation from Average
3!

• Should Be 3 More Accidents Than 1 Per 30 Million
  to Be Significant

14
Pedestrian Usage
330,000 Pedestrians 1 Accident

• 43 Million Pedestrian Crossing Events
• 120 Vehicle / Pedestrian Accidents

15
Effect of Pedestrian Volume
16
Effect of Pedestrian Volume
Accidents / Ped. Crossing Events

• Low Use
• High Use
• Unmarked

1 / 170,000 1 / 440,000 1 / 300,000
17
Crosswalk Usage
18
Contrast to FHWA/UNC Study
FHWA
L.A.
UNC

• High Pedestrian Volumes
• Small Sample

19
Relation to Total Accidents
20
Typical Crosswalk Site

• 8.5 Years of Data
• 5 Total Crash Reports
• 1 Pedestrian Accident
• Site Not on Safety Radar

21
Problem Site

• 8.5 Years of Data
• 27 Total Accident Reports
• 7 Pedestrian Accidents
• Signal Nearly Warranted

22
Relation to Total Accidents

• A Regular Program of Intersection Accident
  Analysis and Countermeasures Should Be Effective
  in Reducing Pedestrian Accidents
• Consider Stronger Measures at Sites Where
  Accident Experience Approaches Warrants and
  Marked Crosswalk Is Present or Desired

23
Conclusions

• Accident Rates Are Startlingly Similar to Rates
  in Santa Ana From 1997
• 1 Per 30 Million Vehicles
• More Pedestrians Improved Accident Rate
• Rates Comparable to or Better Than Unmarked
  Crossing Accident Rates

24
Conclusions

• High Pedestrian Usage Is Strong Justification for
  Markings
• FHWA/UNC Study Recommendations May Not Adequately
  Consider Effect of High Pedestrian Volume
• Los Angeles Practice to Retain Crosswalks With
  High Pedestrian Usage Is Affirmed by Safety
  Analysis

25
Thank You!