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I came across this interesting report from Aviva, which points out the utter uselessness of drivers speeding. It makes it pretty clear why those drivers squeezing past you because you've held up their progress for 3 seconds are not only endangering you, but wasting their time while doing so.

 

https://www.aviva.co.uk/news-and-guides/article/speeding-just-waste-time...

20 comments

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PRSboy [176 posts] 6 months ago
7 likes

In my experience a good decision on which lane to be in at a roundabout etc can make far more of a difference to a journey time. 

What the report does not recognise is that some people like driving fast... its not a means to an end, but an end in itself.  Or, they are not being aggressive to save time, but are being so because they think they are more important than the cyclist.  This is a psychological issue.

Generally, the importance of the time saved is an illusion.  Rush to work, then wonder about making a coffee etc. 

Rarely is the time saved likely to make a real impact, unless you are a medic!

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jollygoodvelo [1701 posts] 6 months ago
3 likes

In urban areas, speeding is pointless.  You save far more time by being in the right lane at the right time, being assertive with road positioning (not the same as aggressive) and using intelligent routing systems (Waze/Google Maps etc) to distribute traffic load over the network - which means that councils need to be cleverer about introducing filtered permeability and other measures to ensure that traffic only distributes over suitable roads rather than creating rat runs.

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madcarew [633 posts] 6 months ago
4 likes

Speeding is pretty pointless unless you have a straight, clear road. I had a 'race' with a friend who is a (weekend) racing car driver, and a pretty aggressive driver. We were both going for a weekend away to a town 200 miles away. I encouraged him to drive in his normal fashion, which is  driving as fast as he could when he could, and overtaking whenever vaguely possible. I drove the same course, leaving 10 mins behind him, and never exceeded 60 mph, or any local speed limits. After nearly  4 hours  he had got to our destination precisely 8 mins quicker than me. This speaks to 2 things, the dearth of overtaking opportunities on NZ roads, and the utter pointlessness of speeding. 

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Simon E [3263 posts] 6 months ago
4 likes

@ madcarew - a mate of mine told me that back in the late 70s he regularly drove home to mid-Wales from Birkenhead and back at the weekend. At first he tried to get there in the shortest possible time (about 2½ hours) but at some point decided to try driving at what he called 'sensible' speeds. He was surprised that his journey was barely any longer - a handful of minutes IIRC.

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PRSboy [176 posts] 6 months ago
1 like

Sort of vaguely connected, what is the view here on traffic calming measures, e.g chicanes, forced give way zones etc?

There are a couple near us which demonstrates the problem they cause- unecessary huge queues in the morning, extra noise and pollution, near misses as people barge through, and I cannot see what good they actually do.  Even the most pathetic car can hit over 30 from a standing start only a few metres on.  Whats more, Mr or Mrs Impatient then has to make up the valuable time lost by driving even quicker!

Seems like removing them would be an easy win to reduce local congestion and improve air quality with no impact on, or possibly improving, safety.

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LastBoyScout [429 posts] 6 months ago
3 likes

Oh, I don't know. On a recent journey, our taxi driver shaved a good hour off the journey with a combination of assertiveness, creative use of what passed for the pavement, sheer bloody minded-ness and not giving much of a toss about oncoming traffic.

That was over 200km and in Nepal, though, so normal rules didn't apply  4

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hawkinspeter [1747 posts] 6 months ago
1 like
PRSboy wrote:

Sort of vaguely connected, what is the view here on traffic calming measures, e.g chicanes, forced give way zones etc?

There are a couple near us which demonstrates the problem they cause- unecessary huge queues in the morning, extra noise and pollution, near misses as people barge through, and I cannot see what good they actually do.  Even the most pathetic car can hit over 30 from a standing start only a few metres on.  Whats more, Mr or Mrs Impatient then has to make up the valuable time lost by driving even quicker!

Seems like removing them would be an easy win to reduce local congestion and improve air quality with no impact on, or possibly improving, safety.

Chicanes can cause a problem when selfish car drivers try to go through them without slowing/stopping when you're trying to go through the other direction on a bike. Maybe it's just me being selfish, but my view is that the traffic calming isn't aimed at bikes (it certainly isn't designed to slow down bikes) so I don't slow down, but expect cars/lorries/buses to do so.

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Canyon48 [869 posts] 6 months ago
3 likes

It's a really interesting mathematical problem, this. In very simplistic terms, there are a number of discrete speeds at which you can travel through a city without having to stop at a red light (and therefore nullifying any gain due to speeding).

I took a stab at trying to calculate the average speed required to get between traffic lights without having to stop (on my commute through Bristol city centre). To calculate this, you need to know how long the traffic lights are green for and how long they are red for, as well as the distance between two sets of lights.

Generally, the speed at which you want to travel is a function of the period of the traffic lights changing colour. This is why sometimes you always get a green light and sometimes you always get a red light. And, interestingly, the speed at which you need to travel to match that period is around 10-15mph (at least for the roads I was looking at).

Which kind of matches with my cycle commute through the city, cars overtake me where they can, then I just leapfrog them as they are queuing for a traffic light, which turns green shortly before I get to it very often.

Cars then get really stuck if there's so much traffic that they have to wait for a couple of cycles of traffic lights - hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

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alansmurphy [1779 posts] 6 months ago
4 likes
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

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BehindTheBikesheds [1729 posts] 6 months ago
3 likes

Was overtaken yesterday whilst doing 27mph in a 30 zone. Despite 3 mini rounabouts and 3/4 mile I arrived at their turning off point 2 car lengths behind but ultimately they delayed my journey by a few seconds as i had to give a gap after they'd overtook and then slowed more at the right turn at the roundabout.
That is obstruction right right there, one which a Met nobber accused a cyclist of doung after forcing him to stop after illegally speeding and close passing him first.
When motorrists push past and indeed dangerously I just want to give them a hard slap, plod don't give a fuck about such driving std, they don't see/won't accept that that is how deaths and serious injuries occur and just let it slide.

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Canyon48 [869 posts] 6 months ago
1 like
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

I'd still say interesting (if maths interests you!). Very useful for city planning etc

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PRSboy [176 posts] 6 months ago
3 likes
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

Presumably the cycle average speed is based on moving time only.

Avatar
Canyon48 [869 posts] 6 months ago
1 like
PRSboy wrote:
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

Presumably the cycle average speed is based on moving time only.

Yep.

It'd be much easier to explain in terms of velocity distribution plots, but I don't have that for the drive.

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alansmurphy [1779 posts] 6 months ago
1 like

I'm interested in how a journey with an average speed of 7mph takes the same time as one at 17mph...

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PRSboy [176 posts] 6 months ago
2 likes
wellsprop wrote:
PRSboy wrote:
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

Presumably the cycle average speed is based on moving time only.

It's moving time only for both. The overall elapsed time is 1 hour for both.

It'd be much easier to explain in terms of velocity distribution plots, but I don't have that for the drive.

Still don't get it.  Assuming the distance is the same, the overall elapsed journey time is the same, and basis of calculation the same, then surely the average speed cannot be different.

Avatar
Canyon48 [869 posts] 6 months ago
2 likes
PRSboy wrote:
wellsprop wrote:
PRSboy wrote:
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

Presumably the cycle average speed is based on moving time only.

It's moving time only for both. The overall elapsed time is 1 hour for both.

It'd be much easier to explain in terms of velocity distribution plots, but I don't have that for the drive.

Still don't get it.  Assuming the distance is the same, the overall elapsed journey time is the same, and basis of calculation the same, then surely the average speed cannot be different.

Yep, I got it the wrong way around! Oops.

It's way easier to explain in terms of velocity distribution and quartile speeds.

I've realised I don't mean "average" speed, I mean quartile speeds. When cycling, the standard deviation of my velocity distribution is much smaller than it is when driving.

I.e. I spend a very long time sat stationary when I drive my commute, but when I'm moving, I'm travelling a lot faster than when cycling. Strava just spits out my cycling data in terms of moving speed.

Avatar
bigshape [182 posts] 6 months ago
1 like
wellsprop wrote:
PRSboy wrote:
wellsprop wrote:
PRSboy wrote:
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

Presumably the cycle average speed is based on moving time only.

It's moving time only for both. The overall elapsed time is 1 hour for both.

It'd be much easier to explain in terms of velocity distribution plots, but I don't have that for the drive.

Still don't get it.  Assuming the distance is the same, the overall elapsed journey time is the same, and basis of calculation the same, then surely the average speed cannot be different.

Yep, I got it the wrong way around! Oops.

It's way easier to explain in terms of velocity distribution and quartile speeds.

I've realised I don't mean "average" speed, I mean quartile speeds. When cycling, the standard deviation of my velocity distribution is much smaller than it is when driving.

I.e. I spend a very long time sat stationary when I drive my commute, but when I'm moving, I'm travelling a lot faster than when cycling. Strava just spits out my cycling data in terms of moving speed.

strava your drive and set it to private?

Avatar
exilegareth [135 posts] 6 months ago
2 likes

My daily commute to work is 60 miles up the A1 in Northumberland.

This morning a police car overtook me on the last stretch of dual carriageway, about twenty miles before Berwick. (Yes, I know it's the main road from England to Eastern Scotland, but big chunks of it aren't dual carriageway and feature all manner of scary junctions.)  

I didn't follow the police car, and tucked in behind a hatchback driven by an old man in a cap. He stuck to 50mph all the way, and I sang along to the CD player. The police car vanished off into the distance, so that even on the long straights I couldn't see him in front of me.

On the way down the hill into Berwick, who was two cars in front of me? Yep, the police car that passed me twenty miles before...

This is normal for my drive to work, and home. Doesn't matter if I speed or not, th e time it takes is decided by things I can't control, like whether there's a tractor in front of me on one of the single carriageway stretches or not.

Avatar
Canyon48 [869 posts] 5 months ago
1 like
bigshape wrote:
wellsprop wrote:
PRSboy wrote:
wellsprop wrote:
PRSboy wrote:
alansmurphy wrote:
wellsprop wrote:

It's a really interesting mathematical problem, this...

 

hence why my average speed on my drive to uni is 7mph and the average on my cycle is 17mph (even though the commute takes me the same time overall).

 

 

Interesting or wrong?

Presumably the cycle average speed is based on moving time only.

It's moving time only for both. The overall elapsed time is 1 hour for both.

It'd be much easier to explain in terms of velocity distribution plots, but I don't have that for the drive.

Still don't get it.  Assuming the distance is the same, the overall elapsed journey time is the same, and basis of calculation the same, then surely the average speed cannot be different.

Yep, I got it the wrong way around! Oops.

It's way easier to explain in terms of velocity distribution and quartile speeds.

I've realised I don't mean "average" speed, I mean quartile speeds. When cycling, the standard deviation of my velocity distribution is much smaller than it is when driving.

I.e. I spend a very long time sat stationary when I drive my commute, but when I'm moving, I'm travelling a lot faster than when cycling. Strava just spits out my cycling data in terms of moving speed.

strava your drive and set it to private?

Thats a good point actually, that way I can compare the actual average moving speed.

Avatar
Yorkshie Whippet [637 posts] 5 months ago
1 like
exilegareth wrote:

My daily commute to work is 60 miles up the A1 in Northumberland.

This morning a police car overtook me on the last stretch of dual carriageway, about twenty miles before Berwick. (Yes, I know it's the main road from England to Eastern Scotland, but big chunks of it aren't dual carriageway and feature all manner of scary junctions.)  

I didn't follow the police car, and tucked in behind a hatchback driven by an old man in a cap. He stuck to 50mph all the way, and I sang along to the CD player. The police car vanished off into the distance, so that even on the long straights I couldn't see him in front of me.

On the way down the hill into Berwick, who was two cars in front of me? Yep, the police car that passed me twenty miles before...

This is normal for my drive to work, and home. Doesn't matter if I speed or not, th e time it takes is decided by things I can't control, like whether there's a tractor in front of me on one of the single carriageway stretches or not.

 

Whilst out of sight the police had carried out one speeding stop, two pee stops and a coffee/donut stop. Thus being more productive with there time.