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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.
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.
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
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
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.
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.
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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Top
The M1 in Hertfordshire is one of the most congested sections of the UK motorway network with daily traffic
Northamptonshire
has been operating the SPECS average speed enforcement
system since 2001.
The A616 Stocksbridge Bypass Trans-Pennine Route is a key
The A77 in Strathclyde is a main trunk road linking the central belt of Scotland with Ayrshire and the west
The M4 10-12 NMIS scheme was a Highways Agency project to upgrade the
Nottingham was the first ever Safety Camera Partnership to install a SPECS average speed enforcement system in 2000.
Tower Bridge is now successfully operating a unique combined speed