U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
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Project: widening of four-lane arterial road | |||
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Planned Improvements: | widening of arterial roadway from four lanes to six lanes | ||
Project Environment: | urban | x suburban | rural |
Project Design Stage: | x conceptual (0 to 30%) | preliminary (40 to 80%) | advanced (over 80%) |
Project Cost: | < $100,000 | $100,000 - $1,000,000 | x >$1,000,000 |
Project Owner: | Collier County, Florida | ||
Road Safety Audit | |||
Date of RSA: | 15-19 November 2004 | ||
RSA Stage(s): | x design stage | RSA of existing roads | |
RSA team: | staff from Collier County, Federal Highway Administration Resource Center, VHB, and Opus Hamilton |
PROJECT BACKGROUND:
Immokalee Road, a County road, is a major east/west arterial connecting residential areas in western Collier County with I-75, US Highway 41, and the City of Naples. The RSA section of the roadway, shown in FIGURE A.8, was widened from two lanes to four lanes in 2002. The four-lane cross-section, shown in FIGURE A.9, was a divided arterial roadway with two through lanes in each direction, a grass median (up to about 40 feet wide), and turning lanes at signalized intersections. The corridor was adjacent to low-density residential, commercial, and institutional land uses, including the North Naples Fire Station No. 42, Gulf Coast High School, Laurel Oaks Elementary School, and several churches.
To accommodate current and forecast future demand, the County was considering additional widening to six lanes. The proposed upgrade would entail widening the road to a six-lane divided urban arterial standard. At the time of the RSA, the widening project was at a conceptual stage. Design documentation consisted of State design practices and the County’s typical section for a six-lane divided urban arterial.
Signalized intersections shown.
FIGURE A.8 RSA SEGMENT (COLLIER COUNTY RSA)
Immokalee Road near Valewood Drive | Immokalee Road in front of schools |
FIGURE A.9 VIEWS OF RSA SITE (COLLIER COUNTY RSA)
KEY RSA FINDINGS AND SUGGESTIONS:
The RSA findings were divided into two parts:
SELECTED SAFETY ISSUE (Number and Description) |
RISK RATING | SUGGESTIONS | |
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1 | accesses off arterial road: Movements at driveways and local road intersections interfere with traffic on Immokalee Road, an arterial road. | D |
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2 | school-related pedestrian and vehicle traffic: Increased volumes, lanes, and width may increase the collision risk for vehicle and pedestrian traffic associated with adjacent schools. | C |
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3 | pedestrian facilities: Pedestrians need to be safely accommodated on the upgraded roadway. | C |
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4 | cycling facilities: Cyclists need to be safely accommodated on the upgraded roadway. | C |
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5 | barriers with curb: The design of roadside barriers must accommodate the proposed barrier curb. | C |
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6 | stakeholder consultation: Widening Immokalee Road may affect the North Naples fire station and may generate an increased need for speed enforcement. | -- |
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SAFETY ISSUE (Number and Description) |
SUGGESTIONS | |
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1 | median treatments: The impact of median treatments on road safety should be considered in this urbanized transition area. |
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2 | road shoulders: Shoulders may be desirable for emergency use, especially where fire-station traffic is expected. |
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3 | signal display: Signal displays should be visible and conspicuous at all times. |
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4 | accommodation of older and unfamiliar drivers: Older and unfamiliar drivers require enhanced signing, pavement marking, and signal displays. |
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KEY LESSONS LEARNED:
In very early-stage design RSAs, a wider scope for safety enhancements exists. This RSA was conducted very early in the planning stage, when the only design documentation was the County’s typical section for a six-lane divided urban roadway. As a result, the RSA was able to consider not only issues related specifically to the proposed widening from four to six lanes (TABLE A.6), but could also suggest additional opportunities, not necessarily related to the specified widening, to enhance road safety (TABLE A.7). Of particular significance was the opportunity to include in the roadway upgrades several measures to accommodate older drivers, which will help to County to implement elements of the Florida DOT’s “Elder Road User Program” on County roads.
See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
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