In the updated 2009 roads programme the Government announced that the 30km section between Junctions 28 and 31 should be included within the second tranche of managed motorway schemes.
Managed motorways is a technology driven approach that aims to make journeys more reliable by controlling traffic flows more effectively through the use of new technologies such as overhead gantries, lane specific signals, and driver information signs.
Arup was appointed for Junctions 28 to 31 to undertake the options phase of early scheme development and input to the outline business case. At that point the published guidance on managed motorways was in its initial development and there was an opportunity to use the project to understand the implications of the guidance in a real project situation for the first time.
Arup worked with the guidance authors looking at ways in which the number of signal and sign gantries could be safely reduced. Through discussion and design we outlined that the number of gantries could be reduced by 23%. If a less guarded approach was taken, a 35% reduction could be achieved.
The more cautious approach was adopted for the outline business case for this project but the guidance was later republished to allow fewer signs and signals to be required on all future schemes.