These are completed using Automatic Traffic Counters, often referred to as an ATC. The usual appearance on-site is a pair of rubber tubes across the road, connected to the ATC machine at one end, on the side of the road. They are an extremely cost-effective method of obtaining a wide variety of data such as classified traffic flow, giving a full breakdown of every type of vehicle that has passed over the tubes, as well as their speeds – all by direction.
A host of other data is also available from ATCs (such as vehicle headway, etc.) but the typical requirements are for flow and speed. A common application is for site access appraisals for determining the correct visibility to be achieved, as well as providing key traffic data for cordon or census studies (usually requested by the highway authority).
For development planning applications, access and visibility can be an important issue. There are set standards for visibility splay based on the prevailing speed limit of the road. In some cases, those standards are appropriate, but in others, they can be onerous and impractical for some sites. By completing an ATC data collection exercise followed by approved numerical analysis we can help you determine the correct visibility for your site.