When designing streets, engineers must ensure that the proposed layout will accommodate the way in which motor vehicles move.
They use the swept path analysis and the AutoTURN programme. It’s a critical piece of kit in any engineer’s toolbox, helping them to see if there is enough space for motor vehicles to move through a space.
For instance, if a refuse truck can’t get through for its collections, the street design has to be changed to accommodate it.
Until now, this software has only been able to simulate the movements of motorised vehicles, meaning the needs of people cycling were often forgotten in the design process.
As a result, cycle paths are often blocked by barriers, cycle tracks are too narrow or people have to make tight and uncomfortable turns.
Many people using a standard bicycle will only be mildly inconvenienced by this, but for those using cargo bikes, tricycles or adapted bikes, this oversight can mean getting stuck, having to re-route via a busy road or being unable to make a trip entirely.
To help address this issue, we have supported the development of a new swept path analysis software which simulates the movement of cycles, ensuring these are fully accounted for in the design process.
New software helps planners design for all cycles
We’ve adapted the swept path analysis to help designers better understand how cycles move and turn. This allows designers to see how much space a bicycle needs and ensures cycling infrastructure can be designed to be more inclusive and accessible.
To develop this deeper understanding of a cycle’s manoeuvrability when turning, our engineers devised and undertook a series of field tests.
We marked out different paths on a quiet London street and followed them as closely as possible, monitoring the rider’s speed and lean angle, recording all the data with cameras.
The results of these tests helped us determine key parameters needed to calibrate the algorithms simulating movements of cycles in the AutoTURN software. For example, we determined how quickly someone can steer from a straight-line path into a curve.
We also gained some insight into the relationship between lean, speeds and radius of curvature: how fast can someone travel around a tight bend, and how far do they need to learn to do so.
Bringing in change to ensure equality
The tool has currently been released in beta version to Sustrans, and we have been busy using it to determine:
- How far apart barriers must be spaced to allow all users access to a path.
- How tight the bend should be on the approach to a bus stop bypass to reduce speeds and minimise potential conflict between people on cycles and bus passengers.
These are just two of the applications for this new and exciting tool. We will be using it on all of our projects, including the National Cycle Network, ensuring paths, streets and places are designed for everyone.
The success of our towns and cities depends on helping everyone move around without the congestion and air pollution that comes with our reliance on the car.
We hope planners and local authorities will use the software to ensure that the needs of people cycling are given the attention they deserve. And that existing and future infrastructure be designed to be inclusive and accessible to all.