DS2 speed cameras - also known as SpeedMaster, Autovision or Autovision 2 - are semi-permanent speed enforcement installations manufactured by Truvelo. They occupy a unique position between fixed and mobile cameras: the detection equipment is installed in the road at a fixed location, but the camera unit and enforcement vehicle are brought to the site when in use. DS2 systems can cover two lanes of traffic travelling in opposite directions simultaneously.
Unlike radar-based cameras such as the Gatso and Watchman, DS2 cameras use three piezo sensors embedded in or laid across the road surface to detect vehicle speed. This means they cannot be detected by a radar detector. The sensors are set approximately 1 metre apart and are accompanied by a short grey roadside box - the most visible indicator of a DS2 site.
DS2 sites are recorded in our database under the mobile speed camera type, which has over 1,300 entries across the UK. To find DS2 enforcement locations near you, search our database for mobile speed camera sites in your county.
How does a DS2 camera work?
A DS2 system detects vehicle speed using three piezo sensor strips laid across the full width of the carriageway, set approximately 1 metre apart. Piezo sensors generate a small electrical signal when pressure is applied - in this case, by the weight of a vehicle's tyres passing over them.
As a vehicle drives over each strip in sequence, the system measures the precise time elapsed between each sensor activation. Because the distance between each strip is fixed and known, the system can calculate the vehicle's speed accurately from the time taken to cover that distance. Three sensors provide two independent speed readings - if the two readings agree, the evidence is reliable and legally admissible.
The sensor data is synchronised with a camera unit which photographs any vehicle recorded above the speed limit. The camera captures the vehicle's number plate and is used to build the evidence record of the offence. Two lanes of traffic travelling in opposite directions can be monitored simultaneously by a single DS2 installation.
The piezo strips can be installed in two ways. Surface-mounted strips are rubber hoses or tubes laid across the road and are visible to drivers as they approach. Embedded strips are cut into the tarmac and fitted flush with the road surface - these are significantly harder to spot, particularly on older or resurfaced roads where the installation may be completely invisible.
Attended and unattended operation
One of the distinguishing features of DS2 systems is that they can operate in two different modes depending on whether enforcement personnel are present at the site.
Attended operation: When the site is staffed, the DS2 detection equipment is connected to a safety camera partnership van or an unmarked police car parked nearby. The Autovision 2 system provides live video evidence of each speeding offence as it occurs, allowing the attending officer to view the offence in real time. In some attended deployments, a police officer waits further along the road out of sight of the camera location. Details of offending vehicles - including the registration number, speed and direction of travel - are transmitted to the officer by radio, allowing them to stop and issue the penalty notice directly to the driver.
Unattended operation: DS2 sites can also be left unattended, with no enforcement vehicle present at the location. In this mode the Autovision system records all vehicle details automatically - number plate, speed, time and date. The evidence is stored and retrieved later for processing. Drivers passing an unattended DS2 site may not be aware it is active, as there is no camera van visible.
This flexibility makes the DS2 particularly effective as a semi-permanent deployment tool - a fixed site can be monitored on some days and left unattended on others, making it difficult for drivers to know when enforcement is active.
How to identify a DS2 site
Identifying a DS2 site with certainty is not always straightforward, particularly compared to large yellow fixed cameras like the Gatso. The key features to look for are:
- A short grey roadside box - this is the most consistent and visible marker of a DS2 site. It is a small grey post or housing unit at the side of the road, typically unobtrusive but present at every DS2 location whether the system is active or not.
- Rubber hoses or tubes across the road - if the piezo sensors are surface-mounted, they will be visible as raised strips running across the full width of the carriageway. They may appear similar to road safety hoses used for traffic surveys.
- No visible camera housing - unlike a fixed Gatso or Truvelo, there is no large yellow camera box mounted on a pole at the site when not in use. The camera unit arrives with the attending enforcement vehicle and is only present during active deployments.
- No enforcement vehicle - in unattended mode, nothing at the roadside indicates whether the system is currently recording. The grey box is the only permanent marker.
If you notice rubber hoses across the road accompanied by a grey roadside box but no camera van, it is possible the site is either unattended or not currently active. Because DS2 sensors can be invisible when embedded in the tarmac, the grey box alone is sufficient reason to be aware that a DS2 site may be present.
Read more about mobile speed camera types ->
Penalties for DS2 speed camera offences
Being caught speeding by a DS2 camera carries the same penalties as any other speed camera in the UK:
- £100 fixed penalty fine
- 3 penalty points added to your driving licence
- An offer to attend a speed awareness course in some cases, as an alternative to points
Depending on the road's speed limit and your recorded speed, a court summons may be generated in place of a fixed penalty notice. This would arrive with the relevant Notice of Intended Prosecution (NIP) code: SP10, SP20, SP30, SP40 or SP50. For more information read our speeding fines guide. For official UK government guidance visit GOV.UK speeding penalties.
