Select Committee on Transport Third Report


113. "Widening the M25 has been likened to digging a ditch in a bog - it fills up as fast as you dig".[220] Mr Hardcastle, Project Director of the ORBIT study illustrated this to us:

"between Leatherhead and the A3 junctions 9 and 10 where it was widened recently from three lanes to four, which represents a 33 per cent increase in capacity, and the traffic flows in the first year after opening increased also by 33 per cent, so all that extra capacity was effectively taken up in the first year after opening, and that pattern has been repeated through many of the sections of the M25 which have been widened".

114. The ORBIT study therefore recommended that the M25 widening be accompanied by area-wide road user charging in 2011 as part of a national scheme. If this were not technically feasible, the study recommends that separate tolling be introduced of those sections that are widened. This option would be less effective and gives a worse economic performance.[221] Failing that, controls on the entry and flow of traffic on the widened roads should be introduced. However, Mr Hardcastle told us that the latter option "would have a limited effect and is really only a short term measure".[222] To illustrate this, the study team found that by 2011, the average time taken to drive the whole way round the M25 was forecast to increase by 8.2 minutes with the latter option but would fall by 16.9 minutes if area-wide charging was introduced.[223]

M6 Midlands to Manchester

115. The M6 Midlands to Manchester study supported the introduction of workplace parking charges and/or congestion charging for Greater Manchester, Merseyside, West Midlands (all at £5 per day) and Stoke/Newcastle (at £2.50 per day).[224] If use of the motorway continued to grow to the extent where reliability was again a problem, the M6 study proposed a £2.50 entry charge for after 2020.[225] The Project Director, Mr Good, told us that the idea was to deter people from making short journeys on the motorway rather than strategic traffic.[226] This appeared to contradict the concerns of other studies that charging to enter motorways alone would create diversion to other, less suitable and less safe parts of the network. However, Mr Good told us that the M6 study considered the congestion implications of the surrounding road network but did not feel that the impacts were significant.[227]

South West Yorkshire Motorway Box

116. Dr Coombe told us that one objective of the study was to achieve an average speed on the strategic road network of 55 miles per hour or above. The Highways Agency and Department were unable to provide advice on whether this was the right level of performance to aim for.[228] The study recommended that area-wide road user charging be introduced as soon as possible and by 2011 at the latest to prevent the benefits of the new roads being removed by too much extra traffic.[229] If charging could not be introduced, other measures of restraining motorway use such as traffic lights on motorway slip roads were recommended.[230] However, this strategy was very much second best as shown earlier in Table 9. Dr Coombe told us that "The combination of road user charging and widening will give you a higher economic return than widening alone. The net present value is orders of magnitude higher than the same widening without charging".[231]

Alternatives to charging

117. The Secretary of State's guidance states that studies should produce a strategy of how to proceed without charging. Many of the studies have suggested that if charging is not introduced then intelligent motorway control systems could reduce congestion.[232] Such systems include Variable Speed Limits such as those on the M25 north of Heathrow Airport and 'ramp metering' where traffic lights on the slip roads control entry to the motorway.

118. The Highways Agency told us that ramp metering had shown benefits in the US. Trials on the M6 and the M27/M3 have been undertaken. However it told us that "it is not yet possible to conclude whether ramp metering is providing benefits".[233] Ramp metering may also cause problems for the surrounding network if queues on the slip road reach back to the roundabout. This limits the scheme's effectiveness. The Variable Speed Limits in operation near Heathrow has received significant driver support. However, the Highways Agency note that "detailed monitoring and analysis of traffic flows, speeds and accidents has so far not demonstrated overall benefits relative to costs".[234]

119. It would be nice if technology were to provide the answer to our congestion problem. However, the conclusions of the studies show that whilst these new systems may show some benefits, they are relatively small and will only have an impact over the short-term. Technology will make a significant but small contribution to reducing the daily congestion on our motorways. It should not be relied on as an effective alternative to inter-urban charging.

220   MMS 05 Back

221   Q546 Back

222   IbidBack

223   ORBIT Final Report, KBR Halliburton, October 2002 Back

224   MMS 53. We note that these assumptions are different from those in the West Midlands Area study and the South East Manchester study Back

225   MMS 53, Q315 Back

226   Q316 Back

227   Q310 Back

228   Q407 Back

229   MMS 05 Back

230   IbidBack

231   Q408 Back

232   MMS 05, MMS 48, MMS 50, MMS 51 Back

233   MMS 54A Back

234   MMS 54A Back

previous page contents next page

House of Commons home page Parliament home page House of Lords home page search page enquiries index

© Parliamentary copyright 2003
Prepared 3 April 2003