Woodlands Park Roundabout

This location had historically been a pedestrian (particularly children from the local school) and driver safety issue for local residents, and an obvious solution was not apparent owing to an unusual combination of topography and road layout. Final roundabout design cost approx. $100K to install. Following a public submission signed by several hundred residents, Duncan Campbell was the traffic engineer responsible for investigating the concerns relating to pedestrian and vehicle safety at this location, and carried through the design to construction.

FIGURE 1: Preliminary sketch showing the project more or less as it was constructed in late 2008 (new islands shown in red over original layout in black & white). The road layout did not lend itself towards a conventional solution, and the central roundabout island was constructed only 20mm high to allow for buses to comfortably turn there in all directions. Deflection through the roundabout was achieved via approach geometry of the new islands.

Key issues relevant to this element: • Analysis of crash patterns at the junction, and site investigations to identify key safety problems which in this case included sight distance limitations due to vertical and horizontal constraints, • This project required an evaluation of several potential options, from simple refuge island to a double-roundabout. The final option was selected following a public meeting with residents where the pros and cons of all options were presented. • The road layout and vertical geometry of the site meant that an unusual roundabout design was required.

Key Outcomes: • The project was constructed in late 2008 and has successfully reduced vehicle speeds and significantly improved pedestrian safety.