Feeling My Age

Transport secretary, Philip Hammond today announced government plans to raise the speed limit to 80mph from 70mph. “Increasing the motorway speed limit to 80mph would generate economic benefits of hundreds of millions of pounds through shorter journey times. So we will consult later this year on raising the limit to get Britain moving” he said.

Predictably, his proposal’s been denounced on grounds of road safety, environmental damage and increased energy consumption. But let’s take a look at the potential benefits.

As a 61 year old commercial traveller I’ve probably done a bit more motorway driving than Philip Hammond and also have some experience of breaking the speed limit. So for me this is a bit of a specialist subject: how much time does increasing your top speed from 70 to 80 actually save on a 100 mile journey ?

Well, at risk of stating the bleeding obvious, every additional 10mph of speed brings diminishing returns. If it was possible to travel the whole 100 miles at top speed without ever slowing down, then:

At 30 mph it would take 200 minutes
At 40 mph it would take 150 minutes
At 50 mph it would take 120 minutes
At 60 mph it would take 100 minutes
At 70 mph it would take 86 minutes
At 80 mph it would take 75 minutes

So even travelling flat-out, increasing speed from 70 to 80 only shaves 11 minutes off the journey time.

But as every boy racer knows, under normal traffic conditions you can only hit top speed in short bursts because of those pesky Other Drivers. How often have YOU been overtaken at speed by some terrifyingly reckless fuckwit – and I speak as a repented sinner – only to end up 10 yards behind him in  stationary traffic a few miles down the road?

Even if it was possible to hit top speed for as much as 50% of your journey, the time saved by that extra 10mph would be just five and a half minutes. So much for those “economic benefits of hundreds of millions of pounds” – you’d probably need the whole five minutes to sit down with a cup of tea and recover from the stress.