The Florida Department of Transportation (FDOT) has been meeting with local officials and community members regarding two planned projects on State Road (S.R.) A1A in Cape Canaveral. The following are questions and FDOT responses related to plans to realign International Drive and construct a roundabout at the new intersection. Questions related to the overall corridor are addressed in a separate document.
The most significant safety benefits of the roundabout are the removal of left turns across oncoming traffic and slower speeds. The roundabout also removes the chances for a head-on collision among vehicles. The left-turn and head-on collisions can lead to more serious injuries and fatalities. A traditional four-legged intersection has 32 conflicts, or points where vehicles could cross paths and collide. The roundabout only has eight conflict points. Roundabouts are geometrically designed to reduce vehicle speeds to generally 25 mph or less, and all turns are right turns. This significantly reduces the severity of crashes over those at traditional intersections. Crashes that do occur are typically low-speed, sideswipe crashes rather than high-speed T-bone collisions that can occur at traditional intersections especially with left-turn movements.
Roundabouts are geometrically designed to reduce vehicle speeds to generally 25 mph or less, and all turns are right turns. This significantly reduces the severity of crashes over those at traditional intersections. Crashes that do occur are typically low-speed, sideswipe crashes rather than high-speed T-bone collisions that can occur at traditional intersections especially with left-turn movements.
Roundabouts also improve pedestrian safety due to the slow speeds and by providing a refuge island. This allows for two simple crossings of one-way traffic. If a pedestrian is hit by a car at 30 mph, there is a 45% chance of serious injury or fatality. At 40 mph, the risk jumps to 85%.
car at 30 mph, there is a 45% chance of serious injury or fatality. At 40 mph, the risk jumps to 85%.
Multiple studies have been done across the country on the safety of roundabouts. For example, in September 2021, Pennsylvania's Department of Transportation released data for 26 roundabouts on state routes at intersections that were previously stop- or signal-controlled. These roundabouts were reviewed based on having at least three years of data available before and after the roundabout's installation. These 26 roundabouts comprise all the roundabouts on state routes that met the review parameters. Department data based on police-submitted crash reports spanning the years 2000 through 2020 shows:
Additionally, modern roundabouts have been shown to shorten travel times for both drivers and pedestrians. Relieving congestion has been proven to help reduce the frequency of vehicle crashes.
Q. How will emergency vehicles use the roundabout? Won't it increase the response time? Will the fire station at Jackson Street stay where it is?
Modern roundabouts are designed with emergency vehicles in mind. Emergency vehicles can travel within a roundabout with no issues. Statistics show that traffic flow through a roundabout is improved over a traditional intersection; thereby decreasing response time. The fire station at Jackson Street will not need to relocate.