Do vehicle activated signs slow traffic?  Image: Creative Commons Attribution-Share Alike 2.5 Generic license

Vehicle speed measurement and enforcement in Cranfield

During the East End Farm planning debate, a traffic survey showed that 85% of the traffic going past the farm entrance did not exceed 31mph (westbound) and 29mph (eastbound).

This data was supplied by the developers (until this month, Central Bedfordshire Council (CBC) hadn’t carried out a traffic count along Bedford Road/High Street since 2011).


Although the CBC highways officer was ‘happy’ with this statistic, it still means that 15% of the traffic was travelling at faster speeds. The developer’s survey even recorded one vehicle travelling over 60mph.

At the moment, permanent speed management in Cranfield uses a mix of speed ramps/bumps and a collection of vehicle activated signs. Critics of speed bumps say that these have a number of unintended consequences. One example is traffic transferring to other roads to avoid the humps.

Also, the extra acceleration and braking caused by speed bumps can contribute to local air pollution.

Research into the vehicle activated signs has found that these can reduce traffic speed by up to 7mph. Although their effectiveness was seen to reduce over time.

As part of a programme of integrated transport works, CBC is currently carrying out an automated traffic counts survey for the signs on Bedford Road and the High Street. Data from these surveys should become available in a couple of months

Current speed limit enforcement

Bedfordshire Police does carry out speed limit enforcement sessions in Cranfield. According to a Freedom of Information request by the Chronicle, the force only uses one location for its mobile camera. This is a spot on the High Street near Townsend Close.

Since 2015, there have been 22 enforcement sessions on the High Street, which generated 160 Notice of Intended Prosecutions. The police camera system does not record the percentage of traffic that was travelling above the speed limit.

Also, on some occasions, Beds Police was not able to carry out enforcement at the site due to parking issues.

The police spokesperson was unable to explain why only this one site was used. When they were told that a resident had concerns over traffic speed along Crane Way, the spokesperson said that this was the first time that anyone has raised issues about this road. They said:

“After receiving a concern from the Cranfield and Marston Vale around vehicles speeding in Crane Way we have installed a data recorder on the road to analyse the traffic on speeds.

“We will then use this data to inform our decisions around what enforcement action may be necessary in the future.”

The police spokesperson said that if a Cranfield resident has concerns around speeding and dangerous drivers, they are advised contact police by calling 101. Anti-social driving can also be reported online.