Just a thought...............................
Just a thought...............................
Author
Discussion

FourWheelDrift

Original Poster:

91,562 posts

304 months

Friday 7th March 2003
quotequote all
After following queues of traffic stuck behind a Micra doing 45mph on a 60mph A road.

If everyone drove at the limit (30mph in a 30, 60mph in a 60 etc...) would there be less congestion or more??????

What do you all think?

Podie

46,646 posts

295 months

Friday 7th March 2003
quotequote all
From what I remember of the concept of road trains, convoys and congestion theory... as long as all the vehicles are travelling at the same speed, then that's the best way to reduce the problem...

planetdave

9,921 posts

273 months

Friday 7th March 2003
quotequote all
The problem is separation distance cos the higher the speed the greater the distance required, which goes up exponentially. So theoreticaly 1mph gets more vehicles on the same road but would obviously get tail backs unless the feeder roads were restricted too. As a compromise 50mph is pretty good(sorry guys but true) as evidenced on M25 temp restrictions (yes, they did think about it!). Isn't it better to keep moving @ 50 rather than doing 90 and then sitting in a traffic jam, cos that is SO frustrating. Its the future if we dont change the vehicle/mile ratio.

Size Nine Elm

5,167 posts

304 months

Friday 7th March 2003
quotequote all

planetdave said:So theoreticaly 1mph gets more vehicles on the same road

0mph would get even more, no gaps between cars. But that's not what roads are for, they are for people getting places. You need two measures: one for an individual - how long does it take them to get to their destination? From the individuals point of view, the faster the better. If there is no restriction to your speed by traffic levels or otherwise, you can choose your own speed.
The second measure is throughput; how many cars can you get down a stretch of road within a certain time. This is important when traffic levels are high. If everyone drives to the 2-second rule, then speed is irrelevant, you get 1800 cars per lane per hour.
Trouble starts when people are travelling at different speeds, and 'waves' start appearing.

NLJdH

238 posts

274 months

Friday 7th March 2003
quotequote all
From what I have seen, hardly anyone obeys the two-second rule. I see people doing 70-90 with about 2-3 car lengths between each other. Lorry drivers are the worst, they come up on you until all you have in your mirror is the make of the truck, and they have to have even longer distances...

Regards,
Nicholas