University of Florida Study of Leading Pedestrian Indicator (LPI) Implementation Found a Range of 25 to 100 Percent Reduction in Vehicle-Pedestrian Conflicts at Test Locations.

LPI implementation demonstrated promising safety effects in reducing the number of vehicle-pedestrian conflicts.

Date Posted
11/28/2023
Identifier
2023-B01808
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Development of Statewide Guidelines for Implementing Leading Pedestrian Intervals in Florida

Summary Information

Pedestrian safety is an ongoing major concern throughout the United States and is one of the highest priorities for the Florida Department of Transportation (FDOT). Vehicles often fail to yield to pedestrians at intersections, especially when pedestrians enter an intersection with a corresponding green signal in the same direction of vehicle travel. Leading Pedestrian Interval (LPI) has been implemented as a low-cost countermeasure to provide pedestrians an advance start before the concurrent green traffic signal to increase pedestrian visibility and safety in crosswalk. This research conducted an integrated study to determine the suitability and effectiveness of LPI implementation at signalized intersections to improve pedestrian safety and to develop statewide guidelines for LPI implementation. 

Methodology

Preliminary LPI implementation guidelines were developed after input was collected among experienced traffic engineers and FDOT District representatives through surveys, interviews, and teleconferences. Data collection and analyses were then conducted before and after pilot LPI implementation at nine selected intersections that covered a geographically-diverse range of environments (urban/ suburban, high/low speed approaches, north/south/central Florida, inland/coastal, etc.), including:

No. Location City Data Collection Date

1.

East leg (northbound right turn), E Fletcher Ave @ USF Palm Dr

Tampa

January 11, 2017

2.

West leg (southbound right turn), E Kennedy Blvd @ N Tampa St

Tampa

December 15, 2016

3.

West leg (southbound right turn), E Fletcher Ave @ N Nebraska Ave

Tampa

December 20, 2016

4.

South leg (eastbound right turn), W University Ave @ NW 13th St

Gainesville

January 31, 2017

5.

South leg (eastbound right turn) and north leg (eastbound left turn), SR A1A @ 178th St

Sunny Isles Beach

February 24, 2017

6.

North leg (westbound right turn), US 41 @ Laurel Rd

Nokomis

April 6, 2017

7.

West leg (southbound right turn), US 1 @ E Broward Blvd 

Fort Lauderdale

April 20, 2017

8.

South leg (eastbound right turn) and east leg (northbound right turn), E Tennessee St @ E Monroe St

Tallahassee

May 11, 2017

9.

East Leg (northbound right turn), SR 200 @ SW 60th Ave

Ocala

July 6, 2017

 

After the LPI approach at each selected intersection was identified, before and after video data of at least eight hours were collected regarding each targeted approach. In the data review process, three pedestrian phases were defined, including LPI phase (“after” data) and the first few seconds of “Walk” signal equal to LPI duration (“before” data), remaining of “Walk” phase (including flashing or count down), and “Do Not Walk” phase. Under different pedestrian signal phases, data were reviewed for pedestrian volume, turning vehicle volume, turning vehicle yielding and non-yielding behavior, vehicle-pedestrian conflict, and pedestrian compliance and non-compliance to pedestrian signal indications. 

Findings

The analysis results show that LPIs were very effective in reducing vehicle-pedestrian conflicts:

  • Proper implementations of LPIs reduced the number of vehicle-pedestrian conflicts at six of eight (75 percent) testing approaches during the entire pedestrian walk phase. The percentage of vehicle-pedestrian conflict reduction ranged from 25 percent to 100 percent. 
  • The implementation of LPIs showed mixed results of drivers’ yielding behaviors. A higher percentage of non-yielding vehicles were observed during the first few seconds equal to LPI length, but a lower percentage of drivers’ non-yielding vehicles were observed during the entire pedestrian walk phase. 
  • Although the risk of drivers’ non-yielding behaviors is lower than the conflicts between vehicles and pedestrians, sufficient attention is still needed on this safety issue. To enhance the safety of pedestrians crossing at signalized intersections, it is recommended to implement static or blank-out “NO TURN ON RED” signs or “TURNING VEHICLES YIELD TO PEDESTRIANS” signs along with an LPI implementation.
  • The implementation of LPIs yielded a trivial adverse or even favorable influence of LPI on intersection operation efficiency. 
  • Proper LPI implementation produced a high utilization efficiency, including achieving a percentage of utilization above 85 percent at seven testing intersection approaches.

Development of Statewide Guidelines for Implementing Leading Pedestrian Intervals in Florida

Development of Statewide Guidelines for Implementing Leading Pedestrian Intervals in Florida
Source Publication Date
12/01/2017
Author
Lin, Pei-Sung;Wang, Zhenyu;Chen, Cong;Guo, Rui;Zhang, Zhao,
Publisher
Prepared by the Center for Urban Transportation Research (CUTR) University of South Florida for Florida Department of Transportation
Other Reference Number
BDV25-977-22
Goal Areas
Results Type
Deployment Locations