High Risk Rural Roads Program
Low Cost Improvement Options for Specific Problem Areas
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| 3M products and expertise help agencies develop
low-cost solutions and on-target funding requests for improving safety on rural roads. |
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Hear from an Expert (video)
Rural roads can benefit from many different low-cost traffic engineering improvements. Attention-getting signage and highly-visible road markings provide measureable improved communication and positive guidance1. In addition, proper use of lighting, shoulder rumble strips and enhanced traffic control devices can cut overall crashes up to 50%2. These are excellent low-cost countermeasures that improve driving safety.
Useful Links:
STOP-Controlled Intersections
More crashes occur at STOP-controlled intersections than at signalized intersections or at intersections with no controlls at all.
Points of conflict can be enhanced through better signage, markings and improved visibility.
| Effective Countermeasures |
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Benefit-Cost Results |
- Install permanent signs such as:
- Larger (48 inch) STOP signs
- Additional advance warning and high visibility signs
- Double-posting of advance warning signs or STOP signs
- Remote-activated flashers on sight-restricted grades
- Utilize high performance, all-weather pavement markings to produce stop bars, turn lanes, symbols and legends at intersections.
- Employ optimal performance retroreflective materials for brighter STOP signs and more visible advance warning signs, especially at night.
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Improve signs and pavement markings
- Reduce crashes: 42%
- benefit cost: 159:1 - 299:13
Double-up Warning Signs
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Useful links
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Transitions
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Reduced speed zones and physical road edges benefit from driver feedback signs and pavement marking.
Speed Transitions
Speed transitions from rural to city streets and physical engineering at road edges pose the potential for higher crash risk. Slowing traffic by as little as one mile-per-hour can reduce accidents by as much as five percent. This fact caused the FHWA to state that "changeable message signs displaying the actual speeds of approaching drivers have been widely used...to enhance driver compliance with speed limits" (MUTCD 11/2003).
Studies of dynamic speed monitory displays such as 3M(TM) Driver Feedback Signs conclude that this technology reduces overall speed, increases conformance with posted speeds and is popular with drivers, nearby residents and businesses as well as with elected officials4.
Encourage speed compliance with a dynamic system that:
- Provides real-time feedback to approaching drivers
- Commands attention with high-visibility fluorescent yellow-green pixels
- Accomodates many different uses and locations
- Operates in all weather conditions
- Logs speed data for before/after substantiation
- Helps improve safety where transition requires speed reduction
Road Edge Transitions
There are several countermeasures to alert people to roadway edges and help them avoid run-off road crashes.
| Effective Countermeasures |
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Benefit-Cost Results |
- Edge line pavement marking on two-lane roadways
- Shoulder, centerline and edge line rumble strips with pavement marking
- Wider longitudinal pavement markings
- Raised pavement markers
- Enhanced curve delineation
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Edge lines:
- Reduce fatality/injury crashes 37%-78%5
- Reduce crashes at access points 46%-63%5
- Benefit-cost 17:15
Shoulder and edge line rumble strips:
- Reduce run-off road crashes by 25%5
- Benefit-cost 2:1 to 22:15 depending on roadway volume and shoulder width)
Raised pavement markers:
- Reduce crashes 7%-10%5
- Reduce nighttime wet weather crashes 24%-33%5
- Reduce nighttime wet weather crashes 24%-33%5
- Benefit-cost 15:1-26:15
Wider longitudinal pavement markings
- Reduce fatality and injury crashes 8%-11%5
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Danger Spots
Hear from an Expert (video)
Improved guidance for hidden and uncontrolled intersections, curves, obstructed views and lane narrowing deliver greater safety on rural roads. Hidden intersections, curves and railroad crossings may require pavement marking, signs and guard rail markings.
| Effective Countermeasures |
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Benefit-Cost Results |
- Edge line pavement marking on two-lane roadways
- Install advisory speed plaques and fluorescent yellow chevrons at curves
- Install a linear delineation system on guard rails to provide positive guidance through roadway geometry changes
- Use high visibility fluorescent and retroreflective signing for improved conspicuity
- Utilize all weather pavement marking for lane lines, symbols, legends and transverse markings
- Install driver feedback signs for speed reduction and traffic calming
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Chevron alignment signs on curves (radii<7 degrees):
Advisory speed plaques at curves:
Converging chevron pavement marking patterns:
- Reduce 85th percentile speeds by 22%-24%3
- Reduce crashes 43%3
Pavement marking symbols and legends at curves:
- Reduce average speeds by 3%-10%3
- Reduce wrong way movements by 93%3
Warning beacon added to warning sign:
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Visibility Maintenance
Hear from an Expert (video)
Faded or degraded signs, outmoded installation practices and visual clutter contribute to high risk situations on rural roads.
Inadequate Performance
Many factors can distract or reduce the capacity to deliver positive guidance to drivers. To improve performance from a maintenance perspective:
- Replace faded or degraded signs with highly visible fluorescent and retroreflective products
- Adopt modern designs and installation practices for signs and markings (position, height, line-of-sight, conspicuity, etc.)6
- Regularly remove obstructions that hinder sign visibility
- Maintain adequate sight distances at intersections and curves
Benefit Cost Results
3M&153: Diamond Grade&153: Retroreflective Sheeting
- Reduce crashes 25% - 48%
- Benefit-cost 10:17
Useful links
References
1 Reducing Crashes at Controlled Rural Intersections > MnDOT Final Report 2003-15 by Kathleen Harder, et. al
2 Low Cost Traffic Engineering Improvements: A Primer
3 "http://www.fhwa.dot.gov/resourcecenter/team/safety/safe_11tcd.cfm"
4 "Long-Term Effectiveness of Dynamic Speed Monitoring Displays (DSDM) for Speed Management at Speed Limit Transitions" Wayne Sandberg et al.
5 FHWA - MUTCD - Pavement Marking Tutorial http://mutcd.fhwa.dot.gov/PavMkgs/Tutorial/wide_lines.htm (FHWA information on wide lines)
6 (Ripley, 2004 ITE Annual Meeting Proceedings regarding 3M Diamond Grade VIP Retroreflective Sheeting)
7 "Reducing Crashes at Controlled Rural Intersections" MnDot Final Report 2003-15 (3M Diamond Grade VIP Retroreflective Sheeting)
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