Apparently reducing driver frustration is...

[cactustwirly]

50mph limits tend to reduce accidents by bunching everyone up with the lorries - that are quite often doing about 56mph anyhow. The idea is that you don't need to overtake and it works quite well, except when the road obviously is suitable for speeds far greater than 60 and you're left feeling like you're wasting your time.

Also, motorways are some of the safest roads and the mean speed of all traffic (which includes HGVs and buses) is about 70mph. Read into that as to how respected the outdated 70mph limit is.

I can count on one hand the amount of times that I have been stuck behind a lorry on a NSL road.

Even then it is possible to overtake safely.

== Doublepost prevention - post automatically merged: 5 Mar 2022 ==

Agreed, and also has environmental benefits by both reducing the number of acceleration events and reducing the amount of fuel burnt.

The so called environmental benefits would be miniscule.
My car burns more fuel travelling at 50mph than 60mph

 

[LSWR Cavalier]

@cactustwirly

More energy to do 50 than 60? Have the laws of physics been secretly changed?

 

[AlterEgo]

@cactustwirly

More energy to do 50 than 60? Have the laws of physics been secretly changed?

Fuel efficiency is calculated in miles per gallon.

Of course his car doing 60 burns more fuel per minute at 60mph than 50mph, but the journey is quicker and the engine runs for a shorter period of time.

 

[cactustwirly]

@cactustwirly

More energy to do 50 than 60? Have the laws of physics been secretly changed?

But the engine is more efficient at 60 than 50, because of the gearing the engine speed is slower as it's in a higher gear.

The oil is hotter and less viscous, so it is providing less resistance.

 

[lachlan]

These questions of efficiency will be irrelevant when vehicles are electric, as will the argument that being stuck in traffic increases pollution due to idling and acceleration.

 

[Bald Rick]

I can count on one hand the amount of times that I have been stuck behind a lorry on a NSL road.

I invite you to drive the A82 from Dumbarton to Crianlarich...

Fuel efficiency is calculated in miles per gallon.

Of course his car doing 60 burns more fuel per minute at 60mph than 50mph, but the journey is quicker and the engine runs for a shorter period of time.

But the engine is more efficient at 60 than 50, because of the gearing the engine speed is slower as it's in a higher gear.

The oil is hotter and less viscous, so it is providing less resistance.

If you drive 100 miles at 60mph, you will burn more fuel than doing it at 50mph.

 

[PG]

I invite you to drive the A82 from Dumbarton to Crisnlarich...

Or from Ellon: A90 to Peterhead; A952 to Fraserburgh...

If you drive 100 miles at 60mph, you will burn more fuel than doing it at 50mph.

Agreed.

 

[ABB125]

I invite you to drive the A82 from Dumbarton to Crisnlarich...

Lovely road when you're chasing a railtour before all the tourists have woken up.

Once they have woken up, progress is somewhat slowed, however! Particularly on the windy, narrow bit along the northern end of Loch Lomond (my southbound journey along that section felt like it took far longer than northbound, though in reality it was probably no more than 5 minutes or so. However there was definitely an element of "driver frustration" when the person at the front of the (very, very long!) queue wouldn't exceed 30mph* at any point on the section). Fortunately, this section is planned to have a (rather spectacular) upgrade, including long viaducts out on the lake.

*I will point out that there are definitely some bits along there that I wouldn't want to take at more than 30mph, but plenty of it is safe for more than that (though obviously if there are two lorries passing, for example, speed will be somewhat reduced!)

 

[Bald Rick]

Lovely road when you're chasing a railtour before all the tourists have woken up.

Once they have woken up, progress is somewhat slowed, however! Particularly on the windy, narrow bit along the northern end of Loch Lomond (my southbound journey along that section felt like it took far longer than northbound, though in reality it was probably no more than 5 minutes or so. However there was definitely an element of "driver frustration" when the person at the front of the (very, very long!) queue wouldn't exceed 30mph* at any point on the section). Fortunately, this section is planned to have a (rather spectacular) upgrade, including long viaducts out on the lake.

*I will point out that there are definitely some bits along there that I wouldn't want to take at more than 30mph, but plenty of it is safe for more than that (though obviously if there are two lorries passing, for example, speed will be somewhat reduced!)

The upgrade is all on line, with the possibility of two short cut-offs on the land side, but no viaducts in the Loch (not lake, ye Sassenach!)

The time difference on that road can be quite spectacular though, depending what time of day you do it. If you can avoid a lorry, bus, or (the absolute worst) a caravan, you can do the stretch pretty quickly. Conversely, it can take ages.

 

[ABB125]

The upgrade is all on line, with the possibility of two short cut-offs on the land side, but no viaducts in the Loch (not lake, ye Sassenach!)

I must admit it's been some time since I last looked at the plans, so I may have been confusing some of the options with what's been chosen as the preferred route. Either way, the upgrade will be welcome!

The time difference on that road can be quite spectacular though, depending what time of day you do it. If you can avoid a lorry, bus, or (the absolute worst) a caravan, you can do the stretch pretty quickly. Conversely, it can take ages.

Oh yes, my trip last summer definitely proved this!
The bit south of Tarbet is very nice, especially at around 0730 on a Saturday. Barely another car in sight! It was a lot busier in the afternoon when I came back, but the traffic was still flowing at virtually 60mph. It shows how effective a modernised single carriageway road can be (as long as the overall traffic volume isn't too high).
Then you hit Alexandria and Dumbarton in the evening peak...

 

[biko]

I lived near the M25 when it first opened, and two of my neighbours promptly took advantage of it to get jobs with far longer commutes than their previous ones. Most road improvement schemes result in more traffic, both on the "improved" part and off it. Road planners seem to assume that people's movements will be the same as they were before the changes they propose.

Depends on the study and models used. I know that for large motorway projects in the Netherlands for example this is taken into account and is also used to estimate the number of casualties if you don't do anything and the number if a road is widened. This is done for both the road itself and the area around it where the project does have an influence on with respect to intensities. I would think a similar method is used in the UK.

 

[LSWR Cavalier]

These questions of efficiency will be irrelevant when vehicles are electric, as will the argument that being stuck in traffic increases pollution due to idling and acceleration.

But not the frustration and anger many drivers feel when waiting a few moments at a level crossing.

I certainly shall not be driving faster to save fuel, as described by others %).