What is SPECS?

SPECS is an average speed enforcement system, using linked cameras that cover a length of road. SPECS has been used in the UK to control speeds at accident hotspots and major roadworks since 1999.

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How does it work?

SPECS uses linked video cameras to monitor a length of road. Linked cameras do not have to be adjacent; they may bracket other cameras within the speed control zone. Despite what you may read in the press, SPECS is not lane specific, or limited to vehicles that enter and exit the zone in the same lane.

The video cameras continuously capture images of vehicles as they pass through the field of view of the camera. Their number plates are read using Automatic Number Plate Recognition (ANPR) and the average speed of the vehicle is calculated between the linked cameras, over the known baseline distance. If this exceeds the Police speed threshold, an offence record is created and violation images and data are logged.

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Casualty reduction

Accident statistics for all permanent SPECS schemes show a significant reduction in the number of collisions and injuries. Driver recognition is very high, resulting in improved behaviour and compliance with the speed limit wherever it is installed.

The result is a safer road, high compliance and low violation levels. In all SPECS schemes that are at least two years old, the Killed or Seriously Injured (KSI) casualty figures drop by at least 50%. The tables below show the casualty reductions seen across a range of UK installations. All data compares annual averages, with at least three years of baseline data.

Roadworks

M1 6a-10 Pre works* During Works**
Damage only collision 99 74
Slight injury collision 211 97
Serious injury collision 9 9
Fatal collision 2 0
* 12 months up to March 2006
** 12 months after March 2006

52% redution in all injury collisions.


Nottingham Results

A6514 Casualties 3km
Annual Average Killed Serious Injury KSI Total % Change
Before*     12
After**     5.33
* Annual average 3 years prior to installation
** Annual average 7 years post installation
-55%

A610 Casualties 3km
Annual Average Killed Serious Injury KSI Total % Change
Before*     5
After**     2.33
* Annual average 3 years prior to installation
** Annual average 7 years post installation
-53%

A631 Casualties 3.5km
Annual Average Killed Serious Injury KSI Total % Change
Before*     2
After**     0
* Annual average 36 months prior to installation
** Annual average 28 months post installation
-100%

B6004 Casualties 2km
Annual Average Killed Serious Injury KSI Total % Change
Before*     4.33
After**     1.23
* Annual average 36 months prior to installation
** Annual average 39 months post installation
-72%

Data up to June 2007


Northampton Results

A43 Casualties 3km
Annual Average Killed Serious Injury KSI Total % Change
Before*     2.67
After**     0.59
* Annual average 36 months prior to installation
** Annual average 61 months post installation
-77.9%

A428 Casualties 4km
Annual Average Killed Serious Injury KSI Total % Change
Before* 2.9 3.6 6.5
After** 0.24 0.72 0.96
* Annual average 50 months prior to installation
** Annual average 50 months post installation
-85.2%

Data up to September 2007


South Yorkshire Results

A616 Casualties 11km
Annual Average Killed Serious Injury KSI Total % Change
Before* 1.5 1.16 2.66
After** 0.25 0.5 0.75
* Annual average 6 years prior to installation
** Annual average 4 years post installation
-71.8%

80 tickets per week typically

Data up to December 2006


Strathclyde Results

A77 Casualties 50km
Annual Average Killed Serious Injury KSI Total % Change
Before* 4.3 17.3 21.7
After** 2 9 11
* Annual average 3 years prior to installation
** Annual average 2 years post installation
-49.2%

4 tickets per week typically

Data up to July 2007

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Traffic flow improvements

Traffic flow through a SPECS speed control section improves considerably, resulting in a safer, smoother and more reliable journey. Vehicles can merge and diverge more easily, allowing drivers to enter or leave the carriageway without speeding up or slowing down to find a gap.

The overall result is a conveyor belt type flow, with uniform speeds, little braking, larger headways and fewer collisions. This delivers safer, more reliable journeys for all road users, whilst maximising throughput on roads with a high traffic volume.



A typical speed profile for a SPECS controlled roadworks. Nearly all vehicles travel at just below the posted speed limit, with very little congestion and a high level of compliance

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Driver behaviour

Driver behaviour is noticeably better with average speed cameras, with compliance maintained throughout the speed restriction zone. Spot speed cameras often cause 'surfing' or sudden braking at the camera, followed by an increase in speed directly after the camera. This results in a wide distribution of speeds and erratic driver behaviour through the monitored area, promoting flow breakdown and congestion.

In contrast to this, average speed enforcement leads to only small speed variations which creates a smooth flow and safer, more consistent driver behaviour. Compliance is very high, with only a tiny fraction of a percentage of drivers receiving tickets. On a major motorway roadworks scheme, the number of tickets issued weekly is in the hundreds against a typical throughput of over one million vehicles, representing an extremely low violation level.





Traffic volumes change dramatically during any 24 hour period, but average and 85th%ile speeds change very little.

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Environmental benefits

Environmentally, driving at a steady average speed with less accelerating and braking will produce lower emissions and burn less fuel. Using average speed monitoring over long distances, this dramatically improves fuel economy and reduces CO2 emissions. In urban environments, speed humps and chicanes could be removed from routes that need to be accessed by the emergency services, allowing streets to be more accessible and safer.

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Where SPECS can be used

SPECS can be used on virtually any public road, from a 20mph urban street to a high speed, multi-lane motorway. Cameras can be configured for a variety of links, covering hundreds of metres or tens of kilometres, with the capability to monitor vehicles entering and leaving the speed control zone in different lanes. The development of SPECS3 networked cameras will allow large areas to be controlled, using remote camera outstations. SPECS3 has been designed for urban networks and multi-lane carriageways, bringing the benefits of SPECS to an even greater range of applications.

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M1 6a-10 Widening
The M1 in Hertfordshire is one of the most congested sections of the UK motorway network with daily traffic
volumes of 160,000 vehicles.
Northamptonshire
Northamptonshire has been operating the SPECS average speed enforcement system since 2001.
South Yorkshire
The A616 Stocksbridge Bypass Trans-Pennine Route is a key
feeder road to the M1.
A77 Strathclyde
The A77 in Strathclyde is a main trunk road linking the central belt of Scotland with Ayrshire and the west
coast port of Stranraer..
M4 10-12 Technology Upgrade
The M4 10-12 NMIS scheme was a Highways Agency project to upgrade the
communications infrastructure between junctions 10 and 12 of the M4.
Nottingham
Nottingham was the first ever Safety Camera Partnership to install a SPECS average speed enforcement system in 2000.
Tower Bridge
Tower Bridge is now successfully operating a unique combined speed
and weight enforcement system.