U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
| REPORT |
| This report is an archived publication and may contain dated technical, contact, and link information |
 |
| Publication Number: FHWA-HRT-11-067 Date: June 2012 |
Publication Number: FHWA-HRT-11-067 Date: June 2012 |
PDF files can be viewed with the Acrobat® Reader®
The Federal Highway Administration Office of Safety Research and Development is focused on improving highway operations and safety by increasing the knowledge and understanding of the effects of intersection design on operational efficiency and safety. In rural areas, four-lane divided access highways often serve as the arteries for mobility and commerce. Local residents and businesses commonly access these highways via two-way stop-controlled intersections. Left turns and through movements onto or across these highways too often result in serious crashes. The restricted crossing U-turn (RCUT) intersection design is intended to address this safety issue. This report includes the results of driver behavior observations at an RCUT intersection in Maryland and the results of an empirical Bayes before after crash analysis for RCUT intersections on two Maryland corridors. This report should be useful to traffic engineers, planners, and officials who are considering safety improvements at unsignalized intersections on four-lane divided highways.
Monique R. Evans
Director, Office of Safety
Research and Development
Notice
This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. This report does not constitute a standard, specification, or regulation.
The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report because they are considered essential to the objective of the document.
Quality Assurance Statement
The Federal Highway Administration (FHWA) provides high-quality information to serve the Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.
Technical Report Documentation Page
| 1. Report No.
FHWA-HRT-11-067 |
2. Government Accession No. | 3 Recipient's Catalog No. | ||
| 4. Title and Subtitle
Field Evaluation of a Restricted Crossing U-Turn Intersection |
5. Report Date June 2012 |
|||
| 6. Performing Organization Code | ||||
| 7. Author(s)
Vaughan W. Inman and Robert P. Haas |
8. Performing Organization Report No.
|
|||
9. Performing Organization Name and Address Science Applications International Corporation |
10. Work Unit No. (TRAIS) |
|||
| 11. Contract or Grant No. DTFH61-08-C-00006 |
||||
| 12. Sponsoring Agency Name and Address
Office of Safety Research and Development |
13. Type of Report and Period Covered
Final Report, May 2008–September 2011 |
|||
14. Sponsoring Agency Code HRDS |
||||
| 15. Supplementary Notes
The Contracting Officer’s Technical Representative (COTR) was Chris Monk (HRDS-30). Joe Bared (HRDO-20) also sponsored this research. |
||||
| 16. Abstract
Four-lane divided highways are an economical design solution to increase the capacity of rural highways compared
to grade-separated limited access facilities. Compared to two-lane undivided rural highways, four-lane divided
highways have markedly lower rates of sideswipe, rear-end, and head-on collisions. However, right-angle crash
rates are markedly higher on four-lane divided highway intersections than at two-lane undivided highway
intersections, largely as a result of left-turn and through movements from minor roads conflicting with far-side
vehicles on the divided highway. The restricted crossing U-turn (RCUT) intersection is a promising treatment to
mitigate right-angle crashes where two-lane minor roads intersect with rural four-lane divided highways. This report includes a comparison of operations at an RCUT intersection in Maryland with a roughly comparable
conventional stop-controlled intersection on the same corridor. It also includes before-after crash analyses for
intersections converted from conventional to RCUT designs on two Maryland highway corridors. The operational
analysis found that conflicts between vehicles entering or crossing the highway from a minor road were reduced,
weaving movements were about the same for the two intersection types, the RCUT design added about 1 min to
travel time for vehicles making left-turn or through movements from the minor road. Three approaches were used to estimate the affect of an RCUT conversion on crashes. All three approaches led to the same conclusion: the RCUT design reduces crashes. A simple 3-year before and 3-year after analysis suggested a 30 percent decrease in the average number of crashes per year. An analysis that adjusted the observed crash rate at RCUT locations for the observed crash rate at nearby conventional intersections on the same corridors suggested a 28 percent decrease in the average annual number of crashes. An empirical Bayes analysis that adjusts for, among other things, the expected number of crashes at similar intersections and average annual traffic suggested a 44 percent decrease in crashes. Furthermore, the analyses suggest an overall reduction in crash severity with the RCUT design. |
||||
| 17. Key Words
Superstreet, Safety, Driver behavior, J-turn, Divided highway intersection, Travel time, Crash analysis, Restricted crossing U-turn |
18. Distribution Statement No restrictions. This document is available through the |
|||
19. Security Classification Unclassified |
20. Security Classification Unclassified |
21. No. of Pages 49 |
22. Price Free |
|
| Form DOT F 1700.7 | Reproduction of completed page authorized |
SI* (Modern Metric) Conversion Factors
