Comments from my personal Traffic Consultant ...
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"Interesting however...
There needs to be a distinction made between major and minor roads. The distinction is raised in the news article but it is quickly passed over – the diagram below is a conceptual diagram which illustrates how the distinctions should be made between a major (national highway) and minor (local street) road. Minor streets with residential land uses would be better served without traffic lights. However, a major road (which I would roughly define as any A-road) requires traffic lights to ensure the controlled interaction of traffic moving in different directions. They are not simply there to be a 'retrospective cure' for main road priority. However, each case needs to be judged on the specific conditions at the site, plus there are political motivations and legal implications to consider too.
Statistically, traffic lights provide the safest traffic management tool currently available for large volumes of traffic on major roads. Roundabouts and Give Ways produce higher levels of incidents and more serious incidents. However, I accept that people are cognitive entities, capable of interactive behaviours and independent thought and traffic signals (by their very nature) assume that people cannot think for themselves. However, the uncontrolled interaction of large volumes of traffic, moving at higher speeds than 30mph, interacting with pedestrians and cyclists at key junction points would result in higher incident rates and the less efficient movement of traffic overall.
I do concede however, that traffic signals are the biggest cause of delay in urban areas, not the volume of cars. The A56 for example has 14 sets of traffic lights between Altrincham and the M60. This is also in the top ten most congested links in Manchester. Whilst I admit this is excessive, the volume of vehicles using the A56 during the AM and PM peak is huge. If all the traffic signals were removed, I suspect that you would end up with faster journey times on the major road (because the flows are heavier) but excessive delays on the approach minor roads because people would be unable to pull into traffic. The traffic on the major road would also be moving at a higher average speed.
Traffic signals are also not simply designed to be static entities. They are capable of interacting with, and responding to, changes in traffic flows. For instance, traffic lights will remain on green along major roads unless a vehicle pulls up to the junction at the minor entry road. Traffic signals are fitted with ‘induction loops’, a strip of electromagnetic copper wire in the floor that is interrupted when a vehicle travels over it (look for a black rectangle strip in the floor at traffic signals), which then let the signal box near the junction know a vehicles is waiting to pull into traffic and changes the signals accordingly. Similarly, if a pedestrian pushes the button at a crossing point, the signal will wait until the safest point in the signal cycle before allowing the pedestrian to cross. If the pedestrian pushes the signal and then walks away from the crossing, an infrared scanner on the top of the signal will detect the pedestrian is no longer waiting to cross and cancel the pedestrian crossing phase in the signal cycle (in theory!).
The 'shared space' concept is an excellent idea and has been applied with some success in European countries - the Netherlands use it as a standard design in housing estates. It allows the creation of place and forces drivers to interact with their surroundings and become consciously aware of the environment around them. It creates a living place rather than a street scene dominated by the car. In my opinion, this is more appropriate for residential areas. For instance, the average pavement width in a residential areas (where people live, walk, interact, kids play and people subconsciously spend a great deal of their lives) is 2m, by contrast, the average roads width is 7m. Why is the car given the majority of the ‘streetscene’ when it is only a casual user? Why is the pedestrian/resident no given priority over this space?
Conceptual diagrams of the difference between a ‘link’ and a ‘place’ – Definition of road classification
(Sorry .. couldn't get these to copy and paste . me being thick .. Kate)
Personally, I realise that traffic signals have a role to play but it’s the associated rubbish that accompanies them and the tendency to overdesign that annoys me! Like putting guard railings around junctions – if you aren’t clever enough to work out that a car moving a 30mph would hurt if you stepped into the road and it hit you then you need to watch a road safety video! The ridiculous thing is those guard railings would have difficulty stopping anything above 30mph from mounting the pavement and they have a tendency to make vehicles ‘flip’ too!
Anyway, that’s my rant! This is all quite up to the minute debate that is occurring – if you want to have a look at a scheme where they have made a reasonable compromise between good quality streetscene and the need to control traffic, look at Kensington High Street in London – it’s quite good but not exceptional. Places should inspire people – anything less is just a compromise."