The Highways Agency Digital Enforcement Camera System 2.0 (HADECS 2.0) is manufactured by Imtech. All HADECS 2.0 cameras operated by the SEU have been installed by Imtech who also perform the calibration testing, any required maintenance and back office operator training.
The HADECS 2.0 speed camera system has Home Office Type Approval (HOTA) for use in detecting and recording evidence of speeding offences on a SMART Motorway in conjunction with Advanced Motorway Indicator (AMI) signs. A copy of this approval can be viewed here: HADECS 2.0 HOTA
The HADECS 2.0 camera system has been designed to accurately measure the speed of vehicles on a SMART Motorway where the speed limit may be reduced from the National Speed Limit (NSL) of 70mph. The current speed limit is indicated on the AMI signs which are mounted on overhead gantries. For a reduced speed limit this would be in the form of mandatory speed limit signs with a red ring. If the NSL is in place it can be indicated by an NSL sign or the AMIs being blank.
HADECS 2.0 cameras are mounted on the gantries over each lane and monitor traffic passing under them. They are connected to sensors in the AMIs and will only enforce the speed limit when they have confirmation that all of the AMIs above open lanes are correctly indicating the current limit.
There is a 1 minute grace period following a change of speed limit being displayed during which time the HADECS 2.0 cameras will not enforce. This is to allow drivers who approached the gantry as the signs changed enough time to safely reduce their speed if they need to do so to comply with the new limit.
If the camera system detects a vehicle is travelling above a preset threshold for the current speed limit the camera is triggered. It then records three images and data of the offence which is transmitted via a secure connection to the SEU office for processing. Every offence is manually checked by a trained member of Police Staff before a Notice is issued to the vehicle's DVLA registered keeper.
Each HADECS 2.0 camera has been installed and tested by Imtech who issue a Calibration Certificate to confirm that the camera is working correctly. They also perform annual calibration testing.
Each time the camera is triggered it records two wide view images of the road so a secondary check of the vehicle's speed can be made by measuring how far it has travelled. There are check marks painted on the road surface which are spaced 2 meters apart to assist with this. A trained member of Police Staff confirms that the result of the secondary check is within the HOTA required tolerance of +/-10% of the primary speed reading before a Notice is issued.