Road Safety Audits (RSA)

Road Safety Audit Case Studies: Using Three-Dimensional Design Visualization in the Road Safety Audit Process

JULY 2013
FHWA-SA-14-003

Technical Documentation Page

Form DOT F 1700.7 (8-72) – Reproduction of form and completed page is authorized

Acknowledgment

Information obtained for this document involved transportation agencies at the Federal, State, and local levels. The Federal Highway Administration (FHWA) and the authors greatly appreciate the cooperation of the Rhode Island Department of Transportation, The Aquidneck Island Planning Commission, the Montana Department of Transportation, the Prince William County Department of Transportation, the Virginia Department of Transportation, the Riverside County Transportation Commission, and the California Department of Transportation.

Table of Contents

• Executive Summary
• Background
• Eight Steps of an RSA
• RSAs: Benefits and Costs
• Purpose
• 3-D Visualization Overview
• Cases in which RSAs May Benefit from 3-D Visualization
• Benefits of 3-D Visualization
• Visualization Development Efforts
• Conclusions and Recommendations
• References
• APPENDIX A: CASE STUDIES
  • RSA No. 1-Defense Highway/Burna Road Corridot, Middletown, Rhode Island
    • Project Background
    • Key RSA Findings and Suggestions
    • Selected Issues beyond the 3-D Model
    • Benefits of the 3-D Visualization
  • RSA No. 2-Road Safety Audit of I-90 Interchanges, Belgrade, Montana
    • Project Background
    • Key RSA Findings and Suggestions
    • Benefits of the 3-D Visualization
  • RSA No. 3-Road Safety Audit of Purcell Road (Route 643), Prince William County, Virginia
    • Project Background
    • Key RSA Findings and Suggestions
    • Benefits of the 3-D Visualization
  • RSA No. 4-Western Terminus of Proposed Mid County Parkway, Riverside County, California
    • Project Background
    • Key RSA Findings and Suggestions
    • Benefits of the 3-D Visualization
• APPENDIX B: CREATION OF 3-D PDF

LIST OF FIGURES

• Figure 1: Typical eight-step RSA process
• Figure 2: Three-dimensional visualization enables an RSA team to drive through a project in the design stage
• Figure 3: RSA team reviewing a 3-D model
• Figure 4: Graphic showing primary routes in Aquidneck Island Transportation Study
• Figure 5: Limits of the entire study area for the RIRSA, including NAVSTA gates 10, 11, 17, 23, and 32
• Figure 6: Plan view of area modeled as part of the RI RSA (roundabout alternative)
• Figure 7: Images from both 3-D models comparing the signalized intersection and roundabout alternatives at Coddington Highway and the proposed connector road (Burma Road South)
• Figure 8: Proposed crosswalk and sidewalk accommodations along Burma Rd South, looking north from Coddington Hwy (left) and south from Gate 17 Access Rd (right)
• Figure 9: Driver's-eye view approaching roundabout along Coddington Highway
• Figure 10: Image from model showing proximity of Sherman Lane to proposed roundabout
• Figure 11: Early morning sun-glare as seen from eastbound Gate 17 Access Rd
• Figure 12: Schematic diagram of the "dog-bone" concept
• Figure 13: Recently implemented road diet on Coddington Hwy, Newport per RSA team recommendations (photo, left: August 2010; photo, right: January 2013)
• Figure 14: Existing and proposed cross sections for Coddington Hwy developed by the RSA team
• Figure 15: General project study area
• Figure 16: Significant traffic congestion on eastbound Amsterdam Road during weekday morning peak
• Figure 17: 3-D model plan view of RSA study area with closeups of proposed right-turn at Jackrabbit Lane and proposed on-ramp from Amsterdam Road
• Figure 18: Southbound right turn at the intersection of Jackrabbit Lane /Amsterdam Road - Existing (L) and Modeled (R) Views Significant right-turn traffic volume obstructs view of approaching through vehicles
• Figure 19: Modeled view of the existing (L) and proposed (R) design at Amsterdam Road and the I-90E on/off-ramp
• Figure 20: Conceptual illustration of the East Belgrade interchange
• Figure 21: General project study area
• Figure 22: 3-D model plan view of RSA study area on Purcell Road
• Figure 23: Shoulder with edge drop-off before (L) and after (R) RSA was conducted. The edge drop-off was immediately corrected following the RSA workshop
• Figure 24: Bird's-eye view of the convenience store and the neighborhood in the background as seen from west of Dumfries Road
• Figure 25: Bird's-eye view of realigned section of road at the west end of the project
• Figure 26: View along westbound Purcell Road approaching convenience store and Dumfries Road
• Figure 27: Study area for Mid County Parkway RSA
• Figure 28: Preferred alignment (Alternative 9) for the western terminus of Mid County Parkway
• Figure 29: Illustration of proposed lane configurations and key 2040 AM peak hour volumes for NB I-215
• Figure 30: Image from 3-D model showing proximity of northbound I-215 entrance ramps from Placentia Ave and Mid County Pkwy
• Figure 31: Mock up of freeway guide signs on Mid-County Parkway
• Figure 32: Mock up of exit sign along I-215
• Figure 33: Photo of existing freeway guide sign in use along I-215
• Figure 34: 3-D image showing wide cross section of I-215 and distance from left lanes to the right edge of the roadway
• Figure 35: Vantage of NB driver on frontage road as seen in plan view
• Figure 36: 3-D Image from 3-D model showing vantage of NB driver on frontage road
• Figure 37: Image from 3-D model showing proximity of bridge structure to ramp terminus
• Figure 38: Image from 3-D model showing potential for overpass structure to obstruct sight distance of drivers at SB exit ramp
• Figure 39: Image from 3-D model showing closeness of interchange ramps and multilane cross section

LIST OF TABLES

• Table 1: Pre-construction Stage RSAs Conducted Using 3-D Visualization
• Table 2: Pre-construction stage RSAs conducted using 3-D visualization
• Table 3: Selected safety issues and suggested mitigating actions on modeled section of roadway
• Table 4: Suggestions on preliminary concept designs for proposed Burma Road South
• Table 5: Selected safety issues and suggested actions for areas beyond the 3-D model
• Table 6: Comparison of the various design alternatives considered by the RSA team
• Table 7: Key safety issues and suggested mitigating actions
• Table 8: Summary of select safety issues and suggested actions