UK-England

Facilities: 
M25
Facility Type: 
motorways
Length of Controlled Section: 
30km
Conditions: 
congestion management
Date Implemented: 
1995
Operational Information
Concerned Vehicles: 
all
Type of Control: 
at first fixed timing plan (failed), automated, driven by MIDAS
Speed Information
Speed Limit: 
regulatory
Speed Variability: 
40, 50, 60 from perturbation point to upstream
Maximum Speed: 
70mph
ITS: 
incident detection, queue detection, flow/speed measurement
Performance Measures
Monitoring Responsibilities: 
Highway agency
Operational Effectiveness: 
consistent and coherent in sequencing of appropriate speed limits,successful tracking of the back of the queue, need to maintain loops, travel times, shockwaves and headways were improved
Lane Speeds: 
One speed limit for all lanes
Enforcement
Enforcement: 
automatic cameras
Operational Experience: 
difficult at first, system not made for all situation; but corrected later