UTAH INTERSECTION SAFETY Recurrent Crash Sites: Identification, Issues and Factors Wayne D. Cottrell, Ph.D., P.E. Sichun Mu, M.S. Department of Civil and Environmental Engineering University of Utah 122 S. Central Campus Drive Salt Lake City, Utah 84112 December 2005 Disclaimer The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the information presented. This document is disseminated under the sponsorship of the Department of Transportation, University Transportation Centers Program, in the interest of information exchange. The U.S. Government assumes no liability for the contents or use thereof. ABSTRACT A study of collisions occurring at intersections along state routes in Utah was conducted. The number of crashes, the crash severity score and, for selected locations, the crash rate were determined and “ranked” for intersections within the Utah Department of Transportation’s Region 1, Region 2, Region 3, Region 4’s three districts, and the entire state. Study periods of ten years (1994-2003) and three years (2001- 2003) were used. The Crash Data Delivery System (CDDS) was used to identify intersections, determine crash frequencies and severities, and find other collision-related statistics. The intersection of Bangerter Highway and 5400 South in Taylorsville experienced the largest number of crashes between 1994 and 2003 (949) and between 2001 and 2003 (296). The intersection of 700 East and 3300 South in South Salt Lake had the state’s highest crash severity score between 1994 and 2003 (9,524.8); the score assigns 1,000 points to a fatal crash, 100 points to an incapacitating injury crash, and so forth. This intersection also witnessed the largest number of fatal crashes between 1994 and 2003 (5). The intersection of 31st and Wall Avenue in Ogden had the highest severity score between 2001 and 2003 (3,394.5). The intersection of Main Street and 800 East in Hyrum had the highest crash rate among intersections between two state routes, at 4.54 per million entering vehicles, based on 2001-2003 data. University Avenue and 900 North in Provo experienced the greatest number of crashes among non-signalized intersections between 1994 and 2003 (623), while Riverdale Road and Pacific Avenue in Riverdale had the highest number between 2001 and 2003 (156). The intersection of U.S. 89 and an unnamed road in Sanpete County, at milepoint 216.54, had the highest severity scores among non-signalized intersections for both the ten- and three- year study periods. Detailed examinations of individual crash sites were not performed in this study, although the report contains some general recommendations. For example, signalization may be a mitigating strategy at certain non-signalized intersections. Red light cameras, pedestrian facilities, bicycling facilities, and the removal of on-street parking are among the numerous interventions that could be considered for reducing and “calming” crashes. Additional analysis should investigate collision types by crash severity at a variety of intersections, crash rates at intersections between state and non-state routes, and variable functional influence areas. The research team considered the CDDS to be a useful tool, and encourage its continued development, including the customization of certain database search procedures. i ii TABLE OF CONTENTS 1. Research Overview..................................................................................................................... 1 1.1 Research Goals and Objectives .......................................................................................... 1 1.2 Research Scope, Approach and Limitations....................................................................... 1 1.3 Crash Data Delivery System............................................................................................... 2 1.4 Definition of an Intersection............................................................................................... 2 1.5 Identification of Hazardous Intersections........................................................................... 3 1.6 Intersection Crash Contributing Factors............................................................................. 4 2. Utah Intersection Safety Overview ........................................................................................... 7 2.1 General Discussion............................................................................................................. 7 2.2 Statewide Intersection Crash Statistics............................................................................... 7 2.3 Fatal Crashes..................................................................................................................... 10 2.4 Intersection Crash Rates ................................................................................................... 11 3. Intersection Crash Statistics by UDOT Region ..................................................................... 21 3.1 Region 1............................................................................................................................ 22 3.2 Region 2............................................................................................................................ 23 3.3 Region 3............................................................................................................................ 24 3.4 Region 4 – Cedar City District ......................................................................................... 25 3.5 Region 4 – Price District................................................................................................... 26 3.6 Region 4 – Richfield District............................................................................................ 27 3.7 Discussion......................................................................................................................... 27 4. Non-Signalized Intersections ................................................................................................... 53 5. Discussion of Intersection Safety Issues ................................................................................. 59 6. Study Intersections................................................................................................................... 61 6.1 Crash Types ...................................................................................................................... 61 6.2 Crash Severities ................................................................................................................ 61 6.3 Direction of Travel ........................................................................................................... 63 6.4 Crash Rates....................................................................................................................... 63 6.5 Collision Types................................................................................................................. 64 6.6 Functional Radius of Influence......................................................................................... 64 7. Usage of the Crash Data Delivery System.............................................................................. 79 7.1 Ranking Intersections by Total Number of Crashes......................................................... 79 7.2 Ranking Intersections by Crash Severity Scores .............................................................. 81 7.3 Locating Intersections with Fatal Crashes........................................................................ 83 7.4 Crash Rates....................................................................................................................... 84 7.5 Non-Signalized Intersections............................................................................................ 84 7.6 Collision Statistics ............................................................................................................ 85 8. References ................................................................................................................................. 87 iii LIST OF TABLES 1.1 Intersection Functional Areas (Distances) ....................................................................................... 3 2.1 Utah Geographical Regions ............................................................................................................. 7 2.2 50 Utah Intersections with a Large Number of Crashes: 1994-2003............................................. 12 2.3 50 Utah Intersections with a Large Number of Crashes: 2001-2003............................................. 13 2.4 50 Utah Intersections with High Crash Severity Scores: 1994-2003............................................. 14 2.5 50 Utah Intersections with High Crash Severity Scores: 2001-2003............................................. 16 2.6 32 Utah Intersections with > 2 Fatal Crashes 1994-2003 & > 1 Fatal Crash 2001-2003 .............. 18 2.7 29 Utah State Route Intersections with Crash Rates > 2: 2001-2003 Data ................................... 19 3.1 UDOT Region 1: 25 Intersections with a Large Number of Crashes: 1994-2003......................... 28 3.2 UDOT Region 1: 25 Intersections with a Large Number of Crashes: 2001-2003......................... 29 3.3 UDOT Region 1: 25 Intersections with High Crash Severity Scores: 1994-2003......................... 30 3.4 UDOT Region 1: 25 Intersections with High