My beloved grandad, Ken Huddart, was a traffic engineer. He dedicated much of his life to traffic safety, and, throughout his tenure at the GLC, was a particular proponent of the introduction of bus lanes and mini roundabouts. This unfortunately makes him one of the most hated men in Britain - few people whose names are entirely unknown are so regularly cursed!

I think that bus lanes and mini-roundabouts are absolutely genius though - and I think the way in which they're genius suggests a useful approach to solving other entirely unrelated problems, which is why I thought I'd add a quick note about them.

Fundamentally Ken treated traffic not as an infrastructure problem but as a behaviour problem, and mini-roundabouts and bus lanes both reflect this thinking. Both of them try to relieve congestion, but rather than building new physical infrastructure and new roads to relieve the pressure, they just apply a little bit of paint to a communicate a different way of using the existing infrastructure to accomplish the same effect.

The mini roundabout takes an intersection that would normally require stopping, and turns it into one that permits continuous flow. Stopping creates a doppler effect of stopping (which I'm calling a 'stoppler' effect) - you stop, and then the slight delay in reaction time means the car behind you stops just that little bit slower - and so on back up the chain. Relatedly, even on roads where no incident has occurred, this wave of brake-lights rippling back and causing ever compounding time-delays can create major traffic jams. This is why you get massive jams when an accident happens on the other side of a dual carriage way, even when the side you're driving on is completely clear - that small initial slow down of people slowing to look, echoes back up the line, becoming a significant stopped period by the time you're several hundred cars back. By directing people to continuous flow rather than necessitated stopping, the whole system moves faster.

Likewise with the bus lane - it seems counter-intuitive that reducing the road area available cars would actually speed up global traffic flow, but it's true. Cars and buses use the roads in very different ways - cars want to stop as infrequently as possible - getting from A to B, buses by their nature, must stop frequently to service their routes. As above - the stoppler effect means that introducing stops introduces significant knock on delays. By separating out the two different use-cases the cars are protected from this, and able to move in a homogenous flow. Average journey times decrease significantly, in places by 16%! and all just with a painted line.

In summary, I think people should be nicer to Ken (even if they have no idea who he is). In my mind he was a great man and a tireless public servant. I also think his way of thinking suggests a useful paradigm - rather than leaping in and trying to solve a first-order problem, it's worth taking a step back and look at the way that people are interacting with the problem. Sometimes just communicating carefully in a different way can change people's behaviour and go a significant way to resolving the issue, without having to build the M25 - whatever your M25 might be...