Turbo Roundabouts: Safety Through Design
Turbo roundabouts are becoming more popular as their efficiency compared to multi-lane roundabouts become more popular. Essentially, turbo roundabouts are defined as multilane oval intersections where three or four roads enter. The center island may or may not be traversable as well as spiral traffic lanes.
Viewed from above, turbo roundabouts may seem simple to do, but considering the many factors that affect traffic, designing one may be harder than expected. Safety is the primary concern with designers having to greatly consider the path of vehicles as they enter and exit through different roads in turbo roundabouts.
Designing Turbo Roundabouts
When creating turbo roundabouts, designers typically have several goals that must be met. This includes but is not limited to the following:
- Obtain a high capacity turbo roundabout that prevents cut off problems due to spiral shape of the roundabout
- Maintaining safety with travelers despite the unfamiliar spiral movement required to transfer from one road to another.
- Safety in entering a new lane while maintaining perfect visibility to avoid crashes.
- Architectural design that prompts driver to slow down on the speed.
Fortunately, several techniques on building turbo roundabouts have been created to ensure that all design challenges are met. Aside from the fact that the roundabout remains safe, it promotes a design capable of having high capacity entrances as well as exits. Following are some of the design innovations used to achieve their functional as well as safety goals:
- The lanes are made narrower, making drivers more conscious of the vehicles moving towards them. This causes them to become more careful with speed.
- Lane markings are specifically created to follow the spiral movement of the road, allowing drivers to easily follow the changes with their steering wheels.
- Opposite entrances offered to no more than two circular lanes.
- Physical dividers ensure that the drivers wouldn’t be changing lanes on the road, minimizing crashes which can be common with spiral roads due to reduced vision.
- Transition axis increases the comfort of driving for the person behind the wheel.
- Extensive amounts of road signs to further help drivers with navigating the turbo roundabout.
- The width of the lanes is typically designed to fit 16.5 meter vehicles while the length offers up to 27 meters of space for the back.
- A mountable splitter island is also present to increase the awareness of drivers.
Turbo roundabouts are definitely the road design of the future. There is a good chance that these designs will become more prevalent, especially in large cities where space is crucial, prompting builders to utilize as little land as possible without sacrificing quality.
Turbo roundabouts have been known to provide the following benefits:
- Less cost for construction. The spiral design makes it possible for the roundabout to accommodate high traffic without spending too much on concrete as well as other building materials.
- The spiral design naturally prompts drivers into driving slower, therefore preventing accidents on the road.