Road Safety Audits (RSA)

APPENDIX A
RSA CASE STUDIES

RSA NUMBER 6

COLLIER COUNTY (FLORIDA):
RSA OF IMPROVEMENTS TO IMMOKALEE ROAD

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:

• issues arising from the proposed upgrade (TABLE A.6):  These issues reflected concerns arising from the proposed upgrading from a four-lane mixed urban/rural arterial to a six-lane urban arterial cross-section, and dealt with properties or specific conditions of the Immokalee Road widening project that could influence design details or require the modification of design standards.
  
  
• further opportunities for improvement (TABLE A.7):  Additional opportunities for improvements that could be incorporated in the upgrading works were also identified.  Although these improvements were not specifically related to the proposed widening, they responded to issues observed along the corridor by the RSA team.   These improvements could be “piggybacked” onto the upgrade project at relatively limited effort and expense.

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.