Rodney Hide on speed

Rodney Hide, who is a mathy kind of guy, writes in today’s Herald on Sunday about the police’s great new idea about how to enforce the speed limit:

Overtaking on the road safely and within the law is now all but impossible.

The speed limit on the open road is 100km/h. The police are applying zero tolerance. You can now be ticketed at 101km/h. The speed limit for heavy vehicles and cars pulling caravans, boats or trailers is 90km/h.

Do the maths. In good driving conditions we are advised to apply the “two-second rule”. At 90km/h that’s 50m. So you pull out 50m behind a truck and trailer, the truck and trailer is 20m long and you pull in once safely 50m past. You have to make 120m to pass safely.

If the truck is doing 90km/h and you stick to 100km/h it takes 43 seconds to gain that 120m.

At 100km/h you will have travelled 1.2km. You must allow for a car coming towards you at 100km/h. To pass safely you need 2.4km of clear road.

That doesn’t happen often.

Cameron Slater comments:

I was dreadful at algebra at school, still am.

I could never see any point to it, especially with the stupid questions like “if train A travels at 90km/h and train B travels at 100km/h and train A leaves station C and train b leaves station D at the same time will they both reach station e at the same time” or some other crap like that.

My answer, which turned out to be wrong every time, was “Check the timetable”.

I digress…Rodney Hide has shown proper use of algebra in slamming the Police’s stupid insistence on zero tolerance of exceeding the speed limit.

So here are Godley and Creme with “The Problem” from their 1981 album Ismism, one of the few songs I know that are about maths: