Driving well below the speed limit

[jfollows]

Cars are required to show a slower speed than the actual speed. Or, at least, never to under-read, which means they will be corrected the other way to make sure.

 

[thejuggler]

Some people are drivers, some people are little more than passengers with a steering wheel in front of them.

When I was doing school run on occasion I'd time it badly and end up behind a driver who would do between 20 and 25mph in a 2 mile stretch of 40 limit.

 

[zwk500]

Cars are required to show a slower speed than the actual speed. Or, at least, never to under-read, which means they will be corrected the other way to make sure.

The speedo however generally isn't more than 10% under. I've compared the GPS speed (android phone on Google Maps) to my analogue speedo regularly on the motorway and it doesn't get more than 5mph out below 60mph. If I have 75mph indicated on the speedo the GPS will generally be showing 69/70mph. If I'm doing 20mph on the GPS it'll be showing 22-23mph ish on the speedo.

 

[Sun Chariot]

It has convinced me that at a minimum, the theory tests should be mandatory to re-take every 5 years. Ideally practical tests as well but there's a limit to instructors and slots, whereas the theory is comparatively easier to administer.

I also agree with this approach and I'd also want it to include a more rigorous assessment for situational / spacial and risk awareness - simulator-based, with a stringent threshold for "pass".

 

[styles]

There's someone in our village who does 40mph in our village (30mph limit), and 40mph when they get to the national speed limit single carriageway (60mph limit for their car).

They're in their 60s, so I assume it's something to do with confidence or reaction times on the country lanes or something.

 

[gabrielhj07]

I put this one down to people being frightened about limits changing and being 'caught out' by the evil speed cameras, so it's safer to stay at 20mph all the time. It's a similar thing with people on motorways avoiding Lane 1 because they're concerned about it suddenly peeling off at the next junction and rather than actually look at signs or the road markings it's easier to be on autopilot so long as there's a lane to your right for anybody who needs to overtake.

I am always amazed how lane discipline improves when the A23 goes from 3 to 2 lanes southbound. It's as if the lack of another lane to the right focuses the minds of the middle lane hoggers.

 

[zwk500]

I am always amazed how lane discipline improves when the A23 goes from 3 to 2 lanes southbound. It's as if the lack of another lane to the right focuses the minds of the middle lane hoggers.

Also helps that it's a lane drop at that junction, so the hoggers just pile on through without noticing.

 

[mike57]

There are occasions where 'under speed' happens and is unavoidable. I had an old series 3 Landrover years ago, empty on a straight main road it was fine, it would cruise along happily at 55 or a bit more as it had overdive, but on one occasion I had to tow a heavy trailer and load back from W Yorkshire with it. Weight was pretty much at permitted tow weight for it. Progress was very pedestrian, but I was aware that I was forming a rolling road block and did pull in a couple of times. Given the weight I didn't even want to go fast downhill. Stuck at 40mph where the meagre hp would allow and was down to 30mph on hills.

More recently (last year) I had to hire and drive a 7.5t large van for the day. I have driven this size of vehicle before, but it was a few years ago, so progress out of Hull towards home was very steady for the first few miles until I got used to it. But again I was aware of my surroundings.

What worries me about underspeeders is that in most cases they seem completely oblivious to their surrondings, road conditions, or anything outside their tin on wheels. As we age obviously senses fail, and that means that before it becomes a medical issue wrt to a driving licence people slow down to remain comfortable. But for me once you cant drive at or close to the national speed limit on a good straight main road in good weather conditions then its time to consider if driving is a good idea.

 

[MotCO]

It's a similar thing with people on motorways avoiding Lane 1 because they're concerned about it suddenly peeling off at the next junction and rather than actually look at signs or the road markings it's easier to be on autopilot so long as there's a lane to your right for anybody who needs to overtake.

I agree that road markers are so important and you should note them and react accordingly. However, approaching Junction 9 (Leatherhead) on the clockwise M25, the line markings between lanes 1 and 2 lengthen, indicating that lane 1 is going to veer off, but it doesn't. It is equally important that the white lines are correctly applied.

To address the OPs concerns, I have two further suggestions. Firstly it is inattention, often caused by looking at mobile phones, messaging, retuning the radio, using the touchpad controls etc.

Secondly, the speed limit display in the car does not always pick up the correct speed limit, so maybe reliance on the display is causing them to slow down. (To give an extreme example, going past a school entrance approaching the junction near Kingston Hospital, my car picks up the speed limit of 5 mph displayed in the school road.)

 

[zwk500]

I agree that road markers are so important and you should note them and react accordingly. However, approaching Junction 9 (Leatherhead) on the clockwise M25, the line markings between lanes 1 and 2 lengthen, indicating that lane 1 is going to veer off, but it doesn't. It is equally important that the white lines are correctly applied.

While I do agree it's important the markings are correctly applied, longer white dashes mean an increased hazard ,such as lane changing due to leaving/merging traffic, while a lane drop is indicated by short white dashes. Compare: https://maps.app.goo.gl/aa51zuQngNZtu9En7 (M25 J9 Clockwise, no lane drop) to https://maps.app.goo.gl/iLUT1BaNmKRR2wS89 (M25 J7 anti-clockwise, lane drop for M23 Brighton/South London).

To address the OPs concerns, I have two further suggestions. Firstly it is inattention, often caused by looking at mobile phones, messaging, retuning the radio, using the touchpad controls etc.

Agree also.

Secondly, the speed limit display in the car does not always pick up the correct speed limit, so maybe reliance on the display is causing them to slow down. (To give an extreme example, going past a school entrance approaching the junction near Kingston Hospital, my car picks up the speed limit of 5 mph displayed in the school road.)

Also agree this is a big issue - I have regularly noticed inaccurate speed limits, including 30mph on a 70mph road, on google maps. It also does not seem to update for temporary speed limits (although there might be rare exceptions?).

 

[jfollows]

I agree with much of the discussion above, but I've come to the conclusion that whereas many of us are conscientious and attentive drivers, a significant subset of drivers aren't.

I have no problem either knowing the speed limit or the speed I'm driving, for example, and the speeding course I went on (for knowingly doing 57 in a 50 limit) showed that almost everyone else in attendance genuinely didn't know the rules and didn't knowingly break them.

I absolutely note the "always drive at 40mph" mob - I try and amuse myself with them because I either end up catching them up all the time in the national speed limit section, or they come roaring up my rear in the 30mph section. I have a good trip to my local tip in Mobberley/Knutsford which is mixed 30mph/NSL road, and I usually see them on it.

But I've had an accident which was definitely not my fault, and I got my repairs paid for, but I realised that being in the right wasn't enough. In the same place I now drive differently to ensure that nobody else can make the same mistake.

I think that's the main thing with age - I'm now aware that other drivers won't do what I think they ought to do, and plan better accordingly. There are just too many inattentive people out there to do otherwise, and I'm a better driver for realising it.

 

[MotCO]

I think that's the main thing with age - I'm now aware that other drivers won't do what I think they ought to do, and plan better accordingly. There are just too many inattentive people out there to do otherwise, and I'm a better driver for realising it.

Experience also gives you a sixth sense, and you are more easily able to identify when a motorist is likely to do something unexpected (e.g. incorrectly indicating at a roundabout - their positioning on the road suggests something different may be afoot.)

 

[bleeder4]

I does interest me how annoyed some people get with the car in front of them not driving at the limit. It's a limit, not a target. I think perhaps people just don't have much patience these days. If I find myself stuck behind a driver going slower than me I'll drop back a bit to give myself a view of the road ahead and wait for an opportunity to overtake. It's irrelevant to me whether that overtaking opportunity appears within a minute, or whether I have to wait for half an hour until I get chance. I don't get impatient simply because I'm having to follow behind a slower moving vehicle. It genuinely baffles me how enraged people get by it.

Also, if I'm in a 30 limit I will tend to keep the speedo needle around the 25 mark. That gives me an extra 5mph to play around with should I need to make any sudden acceleration moves, like overtaking a cyclist or something.

 

[Bald Rick]

I don't get impatient simply because I'm having to follow behind a slower moving vehicle. It genuinely baffles me how enraged people get by it.

Because some of us would rather be spending time doing the things we are travelling to, than behind someone who is delaying us. Would you be happy being on a train that is 15 minutes late because the driver wasnt driving to the speed limit?

 

[bramling]

I does interest me how annoyed some people get with the car in front of them not driving at the limit. It's a limit, not a target. I think perhaps people just don't have much patience these days. If I find myself stuck behind a driver going slower than me I'll drop back a bit to give myself a view of the road ahead and wait for an opportunity to overtake. It's irrelevant to me whether that overtaking opportunity appears within a minute, or whether I have to wait for half an hour until I get chance. I don't get impatient simply because I'm having to follow behind a slower moving vehicle. It genuinely baffles me how enraged people get by it.

Also, if I'm in a 30 limit I will tend to keep the speedo needle around the 25 mark. That gives me an extra 5mph to play around with should I need to make any sudden acceleration moves, like overtaking a cyclist or something.

Because it’s annoying, and especially if you’ve had a long day at work or whatever, you just want to make the journey as smoothly as possible, which doesn’t mean following someone whose speed selection is all over the place for no reason.

My experience is also these drivers also tend to be erratic in other ways, not least what I mentioned elsewhere the frequent situation of being too closely tailgated by the 40-everywhere-brigade when you’re observing a 30 mph limit.

It’s selfish and ignorant, especially those who then take exception to being overtaken.

Also, from a safety point of view, I like to be able to observe the road ahead, both for obstructions and also for issues such as hazardous potholes, or potentially animals that might be about to cross. I can’t do that effectively if there’s something blocking the view ahead, and it’s all very well saying just drop back, but this often introduces other problems. And if you’re being forced to drive artificially slowly, reality is you probably now have someone up your backside, which is potentially a problem if you have to brake suddenly because of a hazard. As I say, causing all this is selfish and ignorant.

 

[zwk500]

It's a limit, not a target.

If there's a good reason to be going slowly then I'm not usually bothered, because I'd likely not be going much or any faster. Equally if somebody is around the speed limit but not at it I don't mind. I tend to only get frustrated at cars that are going slowly enough where I think I'd make significant progress if I can overtake them. If you are going significantly slower and don't have any warning, it's a hazard regardless of how legal you might be.

On a dual carriageway it's slightly different, but if you have clear space to the left of you and aren't making significant progress to the next car I'm going to get frustrated as it means the roadspace is throttled and moving into the right hand most lane means you get the usual suspects sitting on your bumper trying to bully you out of the way before you've completed the overtake. Lane hogging in particular leads to less safe roads as traffic wanting to travel at different speeds is forced to interact more.

 

[Peter Sarf]

I heartily agree, but you asked why people do it.
I have spent, or do spend, an awful lot of time driving on the motorway network between London, Brighton, Bristol and Sheffiled/Leeds/York depending on where I am family have been living. It has convinced me that at a minimum, the theory tests should be mandatory to re-take every 5 years. Ideally practical tests as well but there's a limit to instructors and slots, whereas the theory is comparatively easier to administer. I'd also make the theory test specific to the classes of vehicles driven. The same test for a hatchback shouldn't allow you to drive a vehicle (like a large van) that has different speed limits from the NSL, IMO.

I think having a test more often would be useful and I would like examiners to more thoroughly check the id of the person taking the test.

There are occasions where 'under speed' happens and is unavoidable. I had an old series 3 Landrover years ago, empty on a straight main road it was fine, it would cruise along happily at 55 or a bit more as it had overdive, but on one occasion I had to tow a heavy trailer and load back from W Yorkshire with it. Weight was pretty much at permitted tow weight for it. Progress was very pedestrian, but I was aware that I was forming a rolling road block and did pull in a couple of times. Given the weight I didn't even want to go fast downhill. Stuck at 40mph where the meagre hp would allow and was down to 30mph on hills.

More recently (last year) I had to hire and drive a 7.5t large van for the day. I have driven this size of vehicle before, but it was a few years ago, so progress out of Hull towards home was very steady for the first few miles until I got used to it. But again I was aware of my surroundings.

What worries me about underspeeders is that in most cases they seem completely oblivious to their surrondings, road conditions, or anything outside their tin on wheels. As we age obviously senses fail, and that means that before it becomes a medical issue wrt to a driving licence people slow down to remain comfortable. But for me once you cant drive at or close to the national speed limit on a good straight main road in good weather conditions then its time to consider if driving is a good idea.

Older drivers might be a nuisance BUT it is young drivers that have the serious accidents. Having worked for an insurance company it was so obvious how much young drivers cost in accident claims. But there does come a stage when someone has to stop driving due to age.

Experience also gives you a sixth sense, and you are more easily able to identify when a motorist is likely to do something unexpected (e.g. incorrectly indicating at a roundabout - their positioning on the road suggests something different may be afoot.)

Yes. Over the years I have learnt to expect the unexpected but also to have a better idea of clues.

I does interest me how annoyed some people get with the car in front of them not driving at the limit. It's a limit, not a target. I think perhaps people just don't have much patience these days. If I find myself stuck behind a driver going slower than me I'll drop back a bit to give myself a view of the road ahead and wait for an opportunity to overtake. It's irrelevant to me whether that overtaking opportunity appears within a minute, or whether I have to wait for half an hour until I get chance. I don't get impatient simply because I'm having to follow behind a slower moving vehicle. It genuinely baffles me how enraged people get by it.

Also, if I'm in a 30 limit I will tend to keep the speedo needle around the 25 mark. That gives me an extra 5mph to play around with should I need to make any sudden acceleration moves, like overtaking a cyclist or something.

I think impatience can lead to a rash overtaking manoeuvre.

My worst concern is drivers who cannot see that they are inconveniencing others.

As for speedo accuracy my current car shows 20mph when the Sat Nav shows 19mph.

Now for something I remember from my student days.

Went on a day trip to Oxford by car from Birmingham.
On the way back I was in a car with a male friend driving and getting mad at the girl friend in front driving too slow. It was dark and a windy road (1982). I said to him that I suspected he got a better idea of the road ahead than her because he was benefiting from her headlights which of course were further ahead.

Anyway he eventuall overtook. Straight away he was driving slower than he had when behind her. It really was hard to see. These were old cars with old style headlights.

The point is sometimes the person up front has a harder job to do as it is only their headlights lighting up the way for them.

But in @Bald Rick 's case I thin it was the A1081 which might have been the dead straight A5 ?.

 

[bleeder4]

Because some of us would rather be spending time doing the things we are travelling to, than behind someone who is delaying us. Would you be happy being on a train that is 15 minutes late because the driver wasnt driving to the speed limit?

Yes I see your point. I think it's just because I enjoy driving. So someone being slow in front of me is prolonging my driving experience, meaning I spend more time doing something I enjoy. Same with train journeys. I would have no problem trundling along a main line at 30mph for most of the day.

 

[Bald Rick]

But in @Bald Rick 's case I thin it was the A1081 which might have been the dead straight A5 ?.

Well firstly the ‘A5‘ isn‘t dead straight - it has lots of straights on it, but linked by curves (and in our neck of the woods it is the A5183).

The A1081 is the road formerly knwon as the A6. Wide, clear sightlines, but a combination of curves and traffic make it near impossible to overtake day or night, even if the car in front is doing only 30 (and that does happen !)

 

[AM9]

Because some of us would rather be spending time doing the things we are travelling to, than behind someone who is delaying us. Would you be happy being on a train that is 15 minutes late because the driver wasnt driving to the speed limit?

Whilst I generally agree with the thrust of this discussion, the A1081 between St Albans and Harpenden has three different speed limits between what I regard as the most relevant stretch along it (from the Ancient Briton lights to the Station Road roundabout), - a total of 3.6 miles. Of that distance, about 0.7 miles is 30mph and 1.6 is 40mph, leaving 1.3 miles at 60mph. The difference between travelling at 40mph and 60 mph over the NSL section is just 23 seconds, (assuming an instantaneous acceleration from 40 to 60 and a similar instantaneous braking back down to 40). I suggest that is not really worth getting stressed about, particularly that road because it's unlikely that many vehicles are continuing beyond Harpenden. There are plenty of routes where mile after mile of winding two lane road can be found. One I can name is the A32, south from the A31 at Chawton to the dual carriageway just north of M27 J10. I used to do that every Friday for over a year in 1992/3.

 

[PaulJ]

60mph limit, or national speed limit applies? I’ll drive at a speed appropriate to my immediate surroundings and prevailing conditions in terms of weather and light. I’m quite happy to do my 20 mile commute, which is mainly along a dual carriageway, at 55mph max. I won’t get there any quicker by driving at 70mph. My fuel economy is also improved. I’ll drive faster if I’m holding up other traffic, but on a dual carriageway most other vehicles can overtake, but if the road is quiet I see no need at all to hare along at 70mph.

 

[Bald Rick]

Whilst I generally agree with the thrust of this discussion, the A1081 between St Albans and Harpenden has three different speed limits between what I regard as the most relevant stretch along it (from the Ancient Briton lights to the Station Road roundabout), - a total of 3.6 miles. Of that distance, about 0.7 miles is 30mph and 1.6 is 40mph, leaving 1.3 miles at 60mph. The difference between travelling at 40mph and 60 mph over the NSL section is just 23 seconds, (assuming an instantaneous acceleration from 40 to 60 and a similar instantaneous braking back down to 40)

I was just using this as an example - as you say plenty of other places.

Still, it’s 23 seconds I’d rather have doing something else than staring at the back end of a Nissan Juke.

I’m quite happy to do my 20 mile commute, which is mainly along a dual carriageway, at 55mph max. I won’t get there any quicker by driving at 70mph.

My bold. Genuinely interested why you think not?

I understand the point about fuel economy, and also that you take action if holding up other traffic, which is absolutely the right thing to do.

 

[PaulJ]

I was just using this as an example - as you say plenty of other places.

Still, it’s 23 seconds I’d rather have doing something else than staring at the back end of a Nissan Juke.



My bold. Genuinely interested why you think not?

I understand the point about fuel economy, and also that you take action if holding up other traffic, which is absolutely the right thing to do.

It’s a 20 mile commute door to door, 17 miles on the dual carriageway. The average speed over the 20 miles is usually around 40mph. 20 miles at 40mph is 30 minutes. At a higher average speed of around 42/43, I’ll save myself 3 minutes of driving time. It’s just not worth bothering with for 3 minutes.

 

[Towers]

Yes I see your point. I think it's just because I enjoy driving. So someone being slow in front of me is prolonging my driving experience, meaning I spend more time doing something I enjoy. Same with train journeys. I would have no problem trundling along a main line at 30mph for most of the day.

That’s an interesting viewpoint, certainly. I think for many keen drivers, myself included, the enjoyment of driving includes a degree of being able to ‘get on with it’ - that’s not to say screaming around like a moron, but I certainly get far more driving pleasure out of doing 60mph on a clear stretch of NSL than I do being caught behind a clueless “40mph everywhere” trundler; there’s very little skill or driving input in following someone else’s back bumper. From a ‘driving enthusiast’ perspective, that’s a wasted drive!

 

[D1537]

A couple of months back I joined a queue of around 12 cars behind someone in a small hatchback doing 30 along the NSL B-road I use to get to work. Whilst it's nice and wide and fine for 60mph for most of its length, it does have a number of corners and hills, so overtaking is not always straightforward. As such I (and I'm sure the 12 people in front of me) were very happy to see a police car pull out in front of the dawdler and pull them over. I don't know what happened to them, but people driving like that have been charged with driving without due care and attention before.

 

[jon0844]

When we got back to the test centre and he told me that I’d psssed, he also said that I drove too slowly along that section and that if anyone had come up behind me he would have failed me, because they may have got frustrated and decided to overtake.

Always stuck with me that one.

I am quite happy to have not seen many people here saying 'it's a limit, not a target' which is, frankly, a myth/excuse and will not have been taught by any professional instructor. You must drive to the prevailing conditions so, sure, there are times you can't drive at the limit - but when you can, you should. You should also be able to determine those times when it's not safe to drive at the limit.

You can indeed fail a driving test and you could, although unlikely, get done for it if you were holding up other vehicles and potentially encouraging them to do something dangerous.

I see it on Facebook a lot, with people almost implying that those who dare go at the limit are the dangerous ones. No, it's the hesitant ones who - if they can't drive to the conditions of the road - perhaps shouldn't be driving as I'd be worried about what else they cannot do.

 

[JohnMcL7]

I think in a lot of cases up here people driving at slow speed are tourists visiting the area and unfamiliar with the roads especially with winding scenic roads. Excessively slow speeds can be irritating but it's the variation in speed I find more annoying when drivers slow right down for corners then speed up on the straights so you're constantly having to slow right down as well, speed back up, slow down then of course on a good long straight good for overtaking they boot the throttle and you can't get past safely.

 

[gabrielhj07]

Also, if I'm in a 30 limit I will tend to keep the speedo needle around the 25 mark. That gives me an extra 5mph to play around with should I need to make any sudden acceleration moves, like overtaking a cyclist or something.

Which in reality would be 22/23mph - a whopping 75% of the limit. I'm sure there'd be a few complaints if an Intercity train dawdled around at 94mph.

Whilst I generally agree with the thrust of this discussion, the A1081 between St Albans and Harpenden has three different speed limits between what I regard as the most relevant stretch along it (from the Ancient Briton lights to the Station Road roundabout), - a total of 3.6 miles. Of that distance, about 0.7 miles is 30mph and 1.6 is 40mph, leaving 1.3 miles at 60mph. The difference between travelling at 40mph and 60 mph over the NSL section is just 23 seconds, (assuming an instantaneous acceleration from 40 to 60 and a similar instantaneous braking back down to 40). I suggest that is not really worth getting stressed about, particularly that road because it's unlikely that many vehicles are continuing beyond Harpenden. There are plenty of routes where mile after mile of winding two lane road can be found. One I can name is the A32, south from the A31 at Chawton to the dual carriageway just north of M27 J10. I used to do that every Friday for over a year in 1992/3.

I make the difference 39 seconds over 1.3 miles, but I don't think the small time saving is the issue here. Somebody doing 40 in a 60, in otherwise good conditions, presents themselves as being unaware of both their surroundings and their own driving, and thus a potential hazard. These are also the sort of people who refuse to indicate leaving a roundabout, and stop in yellow boxes.

 

[takno]

Because some of us would rather be spending time doing the things we are travelling to, than behind someone who is delaying us. Would you be happy being on a train that is 15 minutes late because the driver wasnt driving to the speed limit?

Isn't that pretty much exactly what happens with some of the more aggressive professional driving policies now?

 

[Bald Rick]

At a higher average speed of around 42/43, I’ll save myself 3 minutes of driving time. It’s just not worth bothering with for 3 minutes.

But you said you wouldn’t get there any quicker. 3 mins is 10% of the journey - that sounds like it would be quicker!

Pit another way - 6 minutes a day, half an hour a week, 22 waking hours a year, spent unnecessarily. You must have more spare time than I have.

As such I (and I'm sure the 12 people in front of me) were very happy to see a police car pull out in front of the dawdler and pull them over.

Good!

I make the difference 39 seconds over 1.3 miles

Yes, I do too.

Isn't that pretty much exactly what happens with some of the more aggressive professional driving policies now?

I think you mean ‘conservative’ rather than aggressive. But yes. I expect winds of change in that respect soon. A subject for another thread perhaps as @43066 will hunt me down.