#15 – Conversion of 14-foot-wide Outside Lanes to 11-foot Travel Lanes with a 3-foot Undesignated Lane

Fort Lauderdale, Florida

Mark Horowitz, Special Projects Coordinator IV, Bicycle Coordinator, Broward County Dept. of Planning and Environmental Protection

Figure 1. SR A1A with a 0.9 m (3 ft) marked bike lane. Sub-standard width lanes are no longer marked or designated as a bicycle facility.


In the early 1990s, the City of Fort Lauderdale redesigned SR A1A, the famous Fort Lauderdale “strip.” It went from a three-lane cross-section with head-in parking on the ocean side and a narrow sidewalk on the commercial side to a four-lane divided roadway with a 4.3 m (14 ft)–wide outside lane and 2.4 m (8 ft)–wide sidewalks on both sides. Shortly after the completion of the initial redesign, the city began receiving complaints about bicyclist and pedestrian conflicts on the beach side sidewalk. While the typical section included a “bicycle facility,” only the proficient bicyclist was comfortable mixing with traffic in the 4.3 m (14 ft)–wide outside lane. As the complaints continued to rise, the city began requesting that the Florida Department of Transportation (FDOT) add 1.2 m (4 ft) bicycle lanes. There was considerable discussion between the city of Fort Lauderdale, the FDOT and the Broward County Bicycling Advisory Committee about reducing the outside travel lanes to 3 m (10 ft) and putting in 1.2 m (4 ft) bicycle lanes. It was decided to try 0.9 m (3 ft) marked bicycle lanes (Figure 2) next to 3.4 m (11 ft) travel lanes. During discussions, concerns were raised that there might be increases in wrong-way riding and turning conflicts at hotel driveways.


A 0.9 m (3 ft) bike lane was incorporated into the wide outside lane (figure 1). Because this was a pilot project, the existing edge stripe was left in place. Standard bicycle lane pavement markings and signs were added to identify the lane as a bicycle facility.

Evaluation and Results

The project was evaluated by several means. The local bicycle coordinator tested the facility by bicycle; members of the County’s Bicycling Advisory Committee and FDOT Staff conducted observations of the bicyclists on the sidewalk and in the undesignated lane, and surveyed bicyclists using the undesignated lane. In addition, the complaints regarding bicycle and pedestrian conflicts received by the city decreased.

Overall, the evaluation of the facility was positive. The on-bike test by the bicycle coordinator found that while the stripe did provide an additional measure of traffic control and bicyclist comfort level increased, it was the minimum width that should be striped. The observations of bicycle ridership showed a decrease in sidewalk riding and conversely an increase in bicyclists riding in the street. The bicyclist surveys revealed that the majority of bicyclists were glad the lane was present but thought it was too narrow. Before the installation of the lane, the club cyclist typified the bicyclist in the street. After installation, cyclists with a wider variety of experience levels were using the 0.9 m (3 ft) lane. In this instance the concerns about an increase in wrong-way riding were not validated. However, this is most likely because the major attraction to the area is the beach, and there was a significant amount of wrong-way riding on the beach side before the installation. Additionally, wrong-way riding did not increase on the opposite side of the street, nor was there an increase in turning conflicts at the numerous hotel driveways.

While this test was successful, the FDOT ultimately decided to reduce the widths of all four travel lanes to 3.2 m (10.5 ft) and put in a 1.2 m (4 ft) marked bike lane.

Figure 2. Along US 1 an existing 4.2 m (14 ft) outside lane was converted to an 3.3 m (11 ft) travel lane next to 0.9 m (3 ft) undesignated lane, or urban paved shoulder.

Conclusions and Recommendations

The test of the 0.9 m (3 ft) bike lane was successful. It reduced bicyclist and pedestrian conflicts on the sidewalk and increased the bicyclist’s comfort level when riding in the street. The predicted negative impacts of increased wrong-way riding and increased conflicts with turning vehicles did not materialize in this instance.

This design has been slightly modified from the original test and does not include bike lane pavement marking or signs. It is now being used by both the FDOT and Broward County Public Works with about 75 km (47 mi) in place in Broward County. Figure 2 shows U.S. 1 in Fort Lauderdale with a 4.3 m (14 ft)–wide outside lane that has been converted to a 3.4 m (11 ft) travel lane with a 0.9 m (3 ft) undesignated lane.

Broward County has included the 0.9 m (3 ft) undesignated lane in its Land Development Code as a design alternative when right-of-way is constrained. Broward County’s Traffic Engineering Division has made a special effort to stripe a 0.9 m (3 ft) undesignated lane on existing 4.3 m (14 ft) outside lanes. The University of North Carolina Highway Safety Research Center is studying the conversions.

Undesignated lanes are in place or planned for use throughout Broward County on major arterials as well as collectors with ADTs ranging from 25,000 to 45,000 cars per day. As was observed in the original evaluation, the undesignated lane is used by bicyclists of all abilities (figure 4). Because of the 0.9 m (3 ft) width, the design should not be referred to as a bicycle lane but as either a 0.9 m (3 ft) undesignated lane or an urban shoulder.

Because this type of facility provides better direction for the motoring and the bicycling public but does not meet current standards, bicycle signage and pavement markings are not used. Additionally, this facility type has been referred to as an undesignated lane or urban shoulder. It should be noted that referring to this facility as an urban shoulder has occasionally created some confusion during the striping process and has resulted in the lane being placed to the right of a dedicated right turn lane instead of to the left. Additionally, care needs to be taken during the striping process. A slight drift to the right when applying the stripe could easily result in a 0.8 m (2.5 ft) lane.

Costs and Funding

During new construction the installation cost is slightly more than placing an edge stripe. The cost in Broward County to convert a 4.3 m (14 ft) wide lane to an 3.3 m (11ft) travel lane with a 0.9 m (3 ft) undesignated lane is approximately $0.37/ft to stripe the lane. Removal of the edge stripe is approximately $1/ft. Broward County has chosen not to remove the existing edge stripe.



Mark Horowitz
Special Projects Coordinator IV, Bicycle Coordinator
Broward County Dept. of Planning and Environmental Protection.
(954) 519-1487

Beatriz Caicedo, P.E.
FDOT District IV
(954) 777-4336