Truvelo UK’s D-CAM digital speed and red light enforcement camera has now gained UK Home Office Type Approval. The D-CAM has been approved for both front and rear photography which, together with choices for the positioning of road markings for secondary speed checks, dramatically increases siting flexibility, as well for as speed on green enforcement. It also incorporates an effective solution which allows camera operation with newer LED traffic signals.
Truvelo uses an array of three in-ground piezoelectric sensors to trigger the D-CAM. These maximise system accuracy because the positions of both the sensors and the lane markings which provide a secondary speed check are known precisely. They also enable axle-based vehicle classification, which allows the camera to select a lower speed threshold where required, as well as lane identification, which is displayed in the data field of images used as evidence.
The D-CAM operates as a speed camera during traffic signals’ amber, green and amber-to-red grace phases. Single images are used for speed offences. The road markings which provide a secondary speed check are typically situated 1.8m from the last of the three piezoelectric sensors, in line with the UK Home Office’s Speedmeter Handbook, however Truvelo is offering users a new option: a secondary speed check point at 5m from the sensor array. This offers customers greater siting flexibility, particularly at intersections where there may already be other buried sensors such as the loops or magnetometers used for traffic signal control or vehicle presence detection.
Once the amber grace period has passed, the camera switches to red light enforcement mode and takes two images. The first shows true speed and offending vehicles or motorcycles straddling the stop bar. The second is taken 40-50ft (12-15m) later, depending on junction size, and confirms that a red light offence has taken place. A patented solution which forms a part of the Home Office Type Approval is the ability to monitor signal phases on newer-generation LED traffic lights.
The D-CAM’s approval for both front and rear photography not only allows a single camera to be rotated on its post to monitor two different sensor arrays but also enables live enforcement in two directions at the same time – referred to by Truvelo as Simultaneous Bi-Directional (SBD) enforcement. A fixed camera can be used to carry out front plate captures on vehicles travelling in one direction and rear plate captures on vehicles travelling in the other, with the secondary speed check markings positioned at the same point on the road. For a typical village-type installation where road users’ speeds in both directions need to be controlled, this represents an appreciable cost saving over previous-generation solutions which needed two cameras. The D-CAM can also be moved between sites to increase coverage and operational flexibility.
Truvelo supplies a pair of servers capable of managing in excess of 25 D-CAMs. The Truvelo Back Office Server (TBOS) receives encrypted images, stores and writes them to a CD. The CD is then inserted into the Truvelo Violation Manager (TVM) where the images can be viewed. This creates the vital ‘air gap’ required by the UK Home Office for automated enforcement systems. The D-CAM has been designed to be compatible with Startraq and Serco back office systems.
Images, which must be received by the TBOS within 24 hours, are continually transferred via and ADSL line or 3G connection. This provides a constant workflow for back office staff. It is also possible to download images to a shuttle PC should there be delays in connecting ADSL to a new site or if there are issues with the back office connection. The shuttle PC is a transfer device only and images cannot be viewed on it.
“We’ve worked very hard to give the market a highly accurate, digital automated enforcement solution which is both cost effective and cost efficient,” says Peter Hill, Truvelo’s UK Operations Director. “Home Office Type Approval, which is generally accepted to be the world’s most stringent test, emphasises just how successful we’ve been.
“The D-CAM’s various new features make it a formidable presence in the automated enforcement market. The simultaneous bi-directional capability can result in installations that cost between one and a half and one and a third less than previous-generation two-camera set-ups and the extended secondary speed check coverage is a major bonus when looking to site enforcement cameras at crowded and complex intersections. Our ability to work with LED traffic signals also places us ahead of the field.
“D-CAM is available now; the first installations are already taking place and we welcome enquiries as to how this ground-breaking solution can help to transform local authorities’ enforcement operations”.