Unpopular but necessary policy on speed limits?...

[Nick]

Go on, prove it.....

Pretty much every time I"ve been in a 50mph average speed zone, typically roadworks on mways, the traffic flow has been better than the unrestricted parts. (anecdotes aren't data)

I've venture the traffic at 70mph is being snarled up by the fact it is 70mph traffic.

Phantom jams occur when people leave insufficient space between cars and a simple braking manouver cascades into stopped traffic.

The minimum distance to avoid this increases with speed.

Typically cars need to have a larger distance between them the faster the traffic flow. This distance is time based eg"the 2 second rule". Capacity is number of cars per minute. The faster the traffic the fewer cars you get per minute.

The slower the cars the shorter the gap can be (down to a minimum value) and the higher capacity.

Capacity means nothing, that's the most ridiculous thing to say. Let's take the speed all the way down to zero and have every car touching, you can't get capacity any bigger, no one is moving!! 🙄 

[papasmurf]

Go on, prove it.....

Pretty much every time I"ve been in a 50mph average speed zone, typically roadworks on mways, the traffic flow has been better than the unrestricted parts. (anecdotes aren't data)

Every time I go anywhere near the Bristol M4/M5 area (which is always "character building,") being able to do 50mph would be a luxury it is more often than not a stop/start jam.

[BeElBeeBub]

You need to get a firkin of whatever beer you drink and get your arse to junction 23 of the M4

it marks the start of a five mile 50mph limit imposed by twatford

and it blows your ideas out of the water

because 100 miles of 70mph traffic all the way from London is fucked over by this.

every fucking day.

Put simply you are WRONG and i can prove it

Go on, prove it.....

Pretty much every time I"ve been in a 50mph average speed zone, typically roadworks on mways, the traffic flow has been better than the unrestricted parts. (anecdotes aren't data) 

I've venture the traffic at 70mph is being snarled up by the fact it is 70mph traffic.

Phantom jams occur when people leave insufficient space between cars and a simple braking manouver cascades into stopped traffic.

The minimum distance to avoid this increases with speed. 

Typically cars need to have a larger distance between them the faster the traffic flow. This distance is time based eg"the 2 second rule". Capacity is number of cars per minute. The faster the traffic the fewer cars you get per minute.

The slower the cars the shorter the gap can be (down to a minimum value) and the higher capacity. 

[johnofgwent]

With EV's and their onboard software, the car should only start once the insurance cover has been downloaded to the vehicle from the insurance company over your wi-fi.

Then each EV has a built in black box. This tells the insurance company the metrics of your driving; acceleration, corning, GPS speed etc.. Each breach causes the insurance to rise but each increase takes years to decrease. Just means people pay on how they drive, the greater over the highway code someone goes, the greater their insurance is. Imagine someone on £20 a month and by the end of the year, they pay £100 a month. Then the year after, they hit £400 per month. By all means don't pay, but then the insurance policy stops the car because the insurance company couldn't automatically renew it each month.

The technology is on the way, forget about VED etc.. the government should just cream off their share of the insurance payments. The way I see people drive about on the roads, this idea will sort out a lot of idiots.

Sounds fine to me

i will spend the next six months perfecting a hack, then die richer than bezos ...

[papasmurf]

Utter shit, that's because your 100 year old Imp won't hit 70 MPH. Spend some cash ya tight git.

Nick stop lying about me I have NEVER owned an imp and have no desire to.  My comment was because it is always a 50mph limit in the area of the M4/M5 junction, rammed with stopped or slow moving traffic due to road works.

[Nick]

I have yet to achieve 50mph in the vicinity of the M5/M4 juction.  I can usually chat to someone leaning on a shovel.

Utter shit, that's because your 100 year old Imp won't hit 70 MPH. Spend some cash ya tight git. 

[Streetwalker]

Last time anyone did 50mph around here was when the Unigate milk float brakes failed going down Norbury Hill  in 1978 

[papasmurf]

You need to get a firkin of whatever beer you drink and get your arse to junction 23 of the M4

it marks the start of a five mile 50mph limit imposed by twatford

and it blows your ideas out of the water

because 100 miles of 70mph traffic all the way from London is fucked over by this.

every fucking day.

Put simply you are WRONG and i can prove it

I have yet to achieve 50mph in the vicinity of the M5/M4 juction.  I can usually chat to someone leaning on a shovel.

[johnofgwent]

That's a good point and I have.

I don't believe capacity (vehicles per hour past a given point) will be adversely affected.

This seems counterintuitive at first.

If cars traveled with a set distance between them regardless of speed then higher speed would mean higher capacity.

But cars don't. The distance between cars is a function of reaction time and stopping distance and is a time based value eg 2 seconds. In fact this time increases slightly with speed as the stopping distance component dominates over reaction time.

So the net effect is capacity is broadly flat and even increases slightly as speed limits decrease. And this is before you take into account the huge effect of "phantom jams" on capacity. These tend to increase as speed limits go up.

Traffic congestion is not caused by speed limits being too low - do you think our motorways would have higher capacities if we upped the speed limit to 90mph? Would town centers be clearer if we upped the limits to 60mph?  It's other things like junction design, light phasing, driver behaviour etc that cause congestion.

You need to get a firkin of whatever beer you drink and get your arse to junction 23 of the M4

it marks the start of a five mile 50mph limit imposed by twatford

and it blows your ideas out of the water

because 100 miles of 70mph traffic all the way from London is fucked over by this.

every fucking day.

Put simply you are WRONG and i can prove it

[Barry]

That's a good point and I have.

I don't believe capacity (vehicles per hour past a given point) will be adversely affected.

This seems counterintuitive at first.

If cars traveled with a set distance between them regardless of speed then higher speed would mean higher capacity.

But cars don't. The distance between cars is a function of reaction time and stopping distance and is a time based value eg 2 seconds. In fact this time increases slightly with speed as the stopping distance component dominates over reaction time.

So the net effect is capacity is broadly flat and even increases slightly as speed limits decrease. And this is before you take into account the huge effect of "phantom jams" on capacity. These tend to increase as speed limits go up.

Traffic congestion is not caused by speed limits being too low - do you think our motorways would have higher capacities if we upped the speed limit to 90mph? Would town centers be clearer if we upped the limits to 60mph?  It's other things like junction design, light phasing, driver behaviour etc that cause congestion.

It's nothing to do with the distance between cars. It's the 40% extra cars on the carriageway which will cause extra congestion and make accidents more likely.
That is why I think a 120kph speed limit would be fine.
The less time spent on the roads, the less cars on the road at any one time. That's simple enough isn't it?

[BeElBeeBub]

I just had  chat with my neighbour, the insurance for both their cars has gone down as well. (There are not many new cars where I live.)

That might be it, they specifically cited repair costs they have comp insurance. 

These new cars cost a fortune for the smallest ding. 

Crack a bumper and it's not just a fill and spray, it's a whole new assembly complete with parking sensors, cameras and lights that take 3 days to fit. 

[papasmurf]

Interesting.

2 friends have had big increases despite no accidents, moves etc.

Apparently the rise is down to the increased cost (parts and labour) of repairs.

They do live in cities and drive fairly new,  complex and expensive cars so that figures.

I just had  chat with my neighbour, the insurance for both their cars has gone down as well. (There are not many new cars where I live.)

[BeElBeeBub]

Our car insurance cost has gone down this year quite significantly. (Just renewed.)

Interesting. 

2 friends have had big increases despite no accidents, moves etc. 

 Apparently the rise is down to the increased cost (parts and labour) of repairs.

They do live in cities and drive fairly new,  complex and expensive cars so that figures. 

[papasmurf]

And I thought my proposal would be controversial! 😁

Did someome cut you up this morning? 😁

In all seriousness, we sort of already have a sliding scale for insurance costs of being a dickhead, still doesn't seem to stop people being dickheads. Plus the idea of my car not starting because a government server is down somewhere doesn't fill me with confidence!

Actually though, I sort of had the reverse idea. Automatic 3rd party insurance via road tax (or fuel duty). Uninsured drivers are a scourge that hits the innocent hard. Not only are those the most likely to cause accidents the mostikelt not to be insured but there is little you can do to avoid it.

If there was a national 3rd party only scheme paid for by some sort of road tax (maybe fuel, electricity, vehicle tax, road toll whatever) then nobody would ever be hit by an uninsured driver again. You could optionally buy theft, fire, breakdown, and comprehensive insurance to top up the basic package. Probably stick a but of tax on that to top up the national 3rd party scheme as well

Our car insurance cost has gone down this year quite significantly. (Just renewed.)

[BeElBeeBub]

With EV's and their onboard software, the car should only start once the insurance cover has been downloaded to the vehicle from the insurance company over your wi-fi.

Then each EV has a built in black box. This tells the insurance company the metrics of your driving; acceleration, corning, GPS speed etc.. Each breach causes the insurance to rise but each increase takes years to decrease. Just means people pay on how they drive, the greater over the highway code someone goes, the greater their insurance is. Imagine someone on £20 a month and by the end of the year, they pay £100 a month. Then the year after, they hit £400 per month. By all means don't pay, but then the insurance policy stops the car because the insurance company couldn't automatically renew it each month.

The technology is on the way, forget about VED etc.. the government should just cream off their share of the insurance payments. The way I see people drive about on the roads, this idea will sort out a lot of idiots.

And I thought my proposal would be controversial! 😁 

Did someome cut you up this morning? 😁

In all seriousness, we sort of already have a sliding scale for insurance costs of being a dickhead, still doesn't seem to stop people being dickheads. Plus the idea of my car not starting because a government server is down somewhere doesn't fill me with confidence! 

Actually though, I sort of had the reverse idea. Automatic 3rd party insurance via road tax (or fuel duty). Uninsured drivers are a scourge that hits the innocent hard. Not only are those the most likely to cause accidents the mostikelt not to be insured but there is little you can do to avoid it. 

If there was a national 3rd party only scheme paid for by some sort of road tax (maybe fuel, electricity, vehicle tax, road toll whatever) then nobody would ever be hit by an uninsured driver again. You could optionally buy theft, fire, breakdown, and comprehensive insurance to top up the basic package. Probably stick a but of tax on that to top up the national 3rd party scheme as well