Issues Facing the South
Transport Provision
Road
In the UK now, it is not uncommon for each household to own two or even three cars. By building 128,000 new properties in Hampshire, the number of extra cars brought to the area could easily be 250,000 or more. Anyone who lives and commutes in the South of England will know intuitively that an extra 250,000 cars (in Hampshire alone) will gridlock the existing road network. In fact, if the length of road needed to accommodate all these extra cars nose-to-tail is calculated, it comes to an extra 1,000km of road! Clearly this kind of increase cannot be accommodated by the existing network… And do we really want a further 1000km of new road built in addition to all the thousands of new houses?
During the rush hour at present, even the slightest minor incident on the motorway can cause traffic chaos for miles around – some of us commuters already suffer hour-long delays on a regular basis. Worse still, most of the traffic problems are already due to "sheer volume of traffic". The proposed increases in traffic are simply madness.
Article on the Maximum Capacity of the M27
Rail
Currently, at rush hour, commuter trains to and from London are so full that finding a seat is a rare gem of good fortune. In addition, the rail network is operating at near full capacity at these times: it is simply not possible to run trains any closer together (for obvious safety reasons). It is interesting that there appears to be no plan at all to build new railway lines in the region, and if there were, would we want it? Without them, commuting to London at peak times from the South will become impossible in future. Another solution, of course, is not to build the thousands of extra houses.
M27 Congestion - the "2-second rule"
"Only a fool breaks the 2-second rule". A bit harsh perhaps, because driving conditions vary, traffic flow is either more, or less smooth and predictable at different times and forward visibility changes. But it is not a bad rule of thumb if we want to encourage safe progress along our motorways.
But what does this mean for the traffic flow? (and we just need primary school maths, without any complex traffic modelling!)
Suppose you are standing on a bridge over the M27. On average, if there is a 2 second gap between vehicles then every 2 seconds, 3 vehicles will pass underneath, one in each lane. That means that in each hour 5,400 vehicles will pass you. At this "flow rate" all 3 lanes are simultaneously pushing the limits of the "2 second rule".
Now consider the reality. Weather is variable and conditions may make driving more difficult; inexperienced or tired drivers are ahead or behind; a significant proportion of drivers may be unfamiliar with UK driving conditions. Traffic is trying to join from congested junctions.
The Highways Agency maintains excellent records of detailed data on hourly flow rates, so lets look at just one stretch of the M27, the heavily used westbound carriageway between junction 7 (Hedge End) and Junction 5 (Southampton Airport) and just take a typical week beginning Monday 26th November 2007.
Most of the time traffic flows quite freely with average speeds in the 60’s. Look at the 2 hour morning rush from 7am to 9am and the picture changes. Average speeds drop to the 30’s or low 20’s and across the whole week only one hour escaped breaching our averaged "l2-second rule". The peak evening hour to 18.00 is only slightly better.
Champion day of all time appears to have been Friday 22 June 2007 when the 8am peak flow reached 6,611 vehicles per hour, an average gap (over the whole period over all three lanes) of just 1.6 seconds - at an average speed of 49mph. We might conclude that this was a very lucky day for these people, as clearly the sheer volume of traffic had not, on this occasion, led to accidents further along the network.
It is into this scenario that the South East Plan intends to put 80,000 houses, their occupants and their vehicles. 6,000 in a new town straddling Botley and Durley near Junction 7, "linked to Southampton" and 10,000 in a new "Fareham North" town near junction 10.
Of course since the South East economic planners have such a deep understanding of sustainable development they know that this massively increased population will not use their cars, they will instead use buses, presumably travelling in some congestion-immune hyperspace, cycle, walk or stay at home using the internet to boost the vision of a high-tech eco-friendly future.
When the PUSH transport planners release their traffic studies (around March 2008) we will see what they have to say. Remind us… what does a congestion charge camera look like?