Speed limits: Is faster safer?

V-Tom said:

Do you have any references?

..Tom

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I had a link but it no longer exists.
It was a study from the state of Idaho from the 1980s.
The state police did extreme enforcement for a month at 5 mph over the limit (I believe it was still 55 in those days).
After the word got out, everyone slowed down.
I believe collisions were reduced in the area of 40% (if memory serves).
However, fatal collisions were cut to almost zero.

This begs the question, why not maintain it?
It seems the good folks of Idaho were truly upset at getting tickets for 62 mph and the courts and state government agreed with them.
So everyone went back to speeding and the carnage returned.

Blackfin said:

Yup. There are, for example, vast, wide-open stretches of the 407 that are begging for a 120 or 130kph legal limit. Same goes for stretches of the 401 between Kitchener and Windsor or Oshawa and Ottawa. If necessary, speed limits could be throttled back through areas like TO or London much as is done in Germany where Autobahns have stretches of no-limits and strictly policed areas of lower limits.

But that makes too much sense.

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You make a good case Blackfin, but you overlook one thing.
Driving at 120, texting, talking on the cell phone, reading the briefing for the meeting you're late for etc.
The speed limit is what it is because too many drivers are just too irresponsible to justify such a speed limit.

statsman said:

You make a good case Blackfin, but you overlook one thing.
Driving at 120, texting, talking on the cell phone, reading the briefing for the meeting you're late for etc.
The speed limit is what it is because too many drivers are just too irresponsible to justify such a speed limit.

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That's why we have laws against distracted driving and heavy penalties for using a cell phone while driving. Part of the problem is that police and government place so much emphasis on velocity and speed traps that other things like distracted driving, obstructing and the like only get a fraction of the enforcement they should.

This whole argument gets a bit futile... people forget a couple of basic principles that will likely make the case for increasing the limits completely moot: For one, there is a consistent and constant focus in the media on the big horrific crashes, and the people that are getting 172'd. Public perception is radically skewed to hate the speeder. Also, there is the environmental component, where it's a hard sell to ANY politician to do something to increase fuel consumption. As I said before, the majority of trucks were governed long before it was law, and even more so when diesel went up so high in price. There are still active arguments about governing cars, so it's pretty obvious that there will be a loud voice pushing to maintain our limits. Don't forget, these same voices are successfully LOWERING speed limits in city neighborhoods.

Blackfin said:

That's why we have laws against distracted driving and heavy penalties for using a cell phone while driving. Part of the problem is that police and government place so much emphasis on velocity and speed traps that other things like distracted driving, obstructing and the like only get a fraction of the enforcement they should.

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We also have laws against murder, robbery and sexual assault
People do it anyway.

Guys, there is a science to setting speed limits, it is called Traffic Engineering. We don't need to get all emotional and opininated. Time to bone up on our Traffic Engineering.
For 50+ years Traffic Engineers have learned that uniform speed is the goal, it is called the 85th percentile speed. It is the speed that 85% of the traffic is going at or below. This means the top 15% of driver's are the high risk drivers and enforcement is targeted at them. Unfortunately the 400 series highways in ON are set at the 1%, meaning 99% view them as "irrational" a highway engineering term defined below. The 85th percentile in Ontario has been measured by CBC Marketplace Oct/15 as 120-130km/h. The 85th percentile speed is by study the safest speed on a closed access freeway.

From the smart guys at Durham Region Public Works
"A safe and reasonable speed limit is usually set at or below the speed at which 85% of drivers travel. Installing the inappropriate control device or arbitrarily lowering the posted speed limit will result in drivers speeding between control devices to make up for lost time.
Research has shown that most drivers travel at a speed they consider to be comfortable, regardless of the posted speed. Studies undertaken "before" and "after" revised speed limit signs have been posted, have shown that there are no significant changes in average vehicle speeds."

Recall the 400 series highways were posted 112km/hr prior to the gas crisis of 1976.
This created an irrational speed limit.
“Roadways with irrational speed limits tended to have larger differences in travel speeds and higher crash rates,” says Campbell. “These results are consistent with other studies that indicate that lower limits do not have much effect on the speed most drivers choose to travel and do not guarantee a safer road.”

250alp said:

Guys, there is a science to setting speed limits, it is called Traffic Engineering. We don't need to get all emotional and opininated. Time to bone up on our Traffic Engineering.
For 50+ years Traffic Engineers have learned that uniform speed is the goal, it is called the 85th percentile speed. It is the speed that 85% of the traffic is going at or below. This means the top 15% of driver's are the high risk drivers and enforcement is targeted at them. Unfortunately the 400 series highways in ON are set at the 1%, meaning 99% view them as "irrational" a highway engineering term defined below. The 85th percentile in Ontario has been measured by CBC Marketplace Oct/15 as 120-130km/h. The 85th percentile speed is by study the safest speed on a closed access freeway.

From the smart guys at Durham Region Public Works
"A safe and reasonable speed limit is usually set at or below the speed at which 85% of drivers travel. Installing the inappropriate control device or arbitrarily lowering the posted speed limit will result in drivers speeding between control devices to make up for lost time.
Research has shown that most drivers travel at a speed they consider to be comfortable, regardless of the posted speed. Studies undertaken "before" and "after" revised speed limit signs have been posted, have shown that there are no significant changes in average vehicle speeds."

Recall the 400 series highways were posted 112km/hr prior to the gas crisis of 1976.
This created an irrational speed limit.
“Roadways with irrational speed limits tended to have larger differences in travel speeds and higher crash rates,” says Campbell. “These results are consistent with other studies that indicate that lower limits do not have much effect on the speed most drivers choose to travel and do not guarantee a safer road.”

https://www.fhwa.dot.gov/publications/publicroads/13sepoct/02.cfm

Please check out and support www.stop100.ca It shows the 61 other states, provinces and countries that have higher speed limits than Ontar-I-owe. If we believe in government by the people for the people we need to advocate for engineering based limits.

​

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Where did they learn it? What experiments were done? Where are the results presented? What caveats did they propose?

I can't wait for the year 3016 where speed limits are safely set at 5km/h.

Welcome to the future!!!!

Wait! No one will travel in vehicles they would have to control. Unless you are Hans Solo and have a wookie as a co-pilot.


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nakkers said:

I can't wait for the year 3016 where speed limits are safely set at 5km/h.

Welcome to the future!!!!

Wait! No one will travel in vehicles they would have to control. Unless you are Hans Solo and have a wookie as a co-pilot.


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By 2116, all cars will be self-driving, so it won't be a problem.
You can talk on your cell phone and text all you want.
Only motorcycles will be operated by the rider, assuming they have not been banned for this reason.

statsman said:

By 2116, all cars will be self-driving, so it won't be a problem.
You can talk on your cell phone and text all you want.
Only motorcycles will be operated by the rider, assuming they have not been banned for this reason.

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Traffic that all travels at or near the same speed tends to be the most safe.

We're moving toward the elimination of personal vehicles, completely, in urban areas. There won't be any cars or motorcycles. It will be high density housing with public transit, of various forms, all controlled by computer.

When I lived in BC they raised the limit on a number of the provincial highways to 120.

There was no significant increase or decrease in the accident rate. I'll find a link to the report.

The interesting thing I found is that i drove at 120 on those highways before and continued to drive at 120 afterwards.

Clem said:

When I lived in BC they raised the limit on a number of the provincial highways to 120.

There was no significant increase or decrease in the accident rate. I'll find a link to the report.

The interesting thing I found is that i drove at 120 on those highways before and continued to drive at 120 afterwards.

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And they just did so much more comfortably, knowing that they didn't need to fear arbitrary and punitive enforcement of abnormally low speed limits as found in places like, say, Ontario.

250alp said:

The 85th percentile in Ontario has been measured by CBC Marketplace Oct/15 as 120-130km/h. The 85th percentile speed is by study the safest speed on a closed access freeway.

​

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If the 85th percentile was measured by CBC while there was a speed limit in place and the threat of enforcement of that limit then it's not really the 85th percentile. I'd imagine the 85th percentile (measured in good weather conditions with light traffic) of the 401 is higher than 130km/h but it could only be properly measured if there was no limit in place and no threat of a speeding ticket.

As someone who drives all over rural Ontario for work I find our limits absolutely ridiculous. Rural roads can have the same characteristics (# of driveways, turning points, visibility, shoulders, ect) and the limit can range from 40km/h - 80km/h. It seems as if there's no uniformity at all in deciding whats a 50, 60, 70 or 80. Two streets over a road can have the same characteristics and the limits can be vastly different. And most of these limits are less than the 5th percentile on the roads - literally no one is going at the speed limit let alone treating it as the "Maximum Safe Speed" (understandably).

The entire speed limit system in our province is flawed. The limits seem to have very little to do with the engineering of the road and far more to do with the preference of whoever was in charge of setting the limit that day. There's also the frustration of slower limits that start well before and end well after the characteristics of the road change (Erin's 40/km/h limits, North and South Service roads 50km/h and 60km/h). And more frustrating are the highways with limits so below the average diving speed that it's a danger to do the limit (the Hanlon Parkway, parts of which would be 130km/h in other countries and here you lose your vehicle at that speed, the 90km/h sections of the 403 and QEW).

If the speed limits were set to the same standard that they are on dense neighborhood roads with 50km/h limits (think Milton, just not Ontario St) we'd actually have limits that reflect the maximum safe speed. Often, when I'm driving on those types of roads with homes on either side I'm driving under the limit because in that type of setting 50 is actually the maximum safe speed to do. If we applied that same standard to our rural roads and highways we'd have much much faster limits and we'd all be better off for it.

85th % studies are always done with existing speed limits in place. Agree with everything else Mike. Ck out www.stop100.ca excellent info by Chris K.

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.no

250alp said:

85th % studies are always done with existing speed limits in place. Agree with everything else Mike. Ck out www.stop100.ca excellent info by Chris K.

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It seems like an obvious issue with 85 percentile studies. If you have a new 85 percentile after a limit is raised what good was the first change in limit.

mikeherdes said:

It seems like an obvious issue with 85 percentile studies. If you have a new 85 percentile after a limit is raised what good was the first change in limit.

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It's common for the 85 percentile to remain stable even with the change in posted limit.

Don't ask me to quote sources. I'm too lazy to find at the moment.


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We need better trained drivers and riders.


Honesty offends fools

Rob MacLennan said:

Traffic that all travels at or near the same speed tends to be the most safe

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Which has the potential to open a can of worms if the limits are raised since truck fleets are unlikely to just go along with the increase given the cost of fuel, and already incredibly tight margins. So, fleets like my companies, with thousands of trucks, as well as most other large fleets..will continue at 100K.

Let's not forget that LCV's in Ontario are also limited to 90KPH, potentially making the gap even more massive. Cars now zipping along at 130 (given a 120 limit, which of course most people inevitably still exceed within what they consider "acceptable" margins) means there's at least a 30KPH gap between them and most trucks, and a 40KPH gap between them and LCV's.

lil red bird said:

We need better trained drivers and riders.

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You've got that right...better training, and some type of semi-regular testing after the fact would be great. Right now an increasingly large percentage of glass G drivers on our roads have no business being there, particularly in urban areas where it seems the driver mills are able to pump out people who are barely able to meet the (laughably low) minimum test requirements, and have little or no skills beyond those already ridiculously low minimums.

But, of course, public perception on that would be "government tax grab!", so nobody in power has the balls to make that sort of thing happen.

What's weird?

Collision rates, fatality rates, injury rates per kilometres drives and per 100 thousand licences drivers have been steadily declining.

Yet insurance rates continue to rise.

We are told the cost of claims and fraud rises.

Distracted driving is on the rise.

But our roads have never been safer?

I don't know folks?

I think we should have realistic posted limits and strict enforcement of those limits.

Doesn't seem to make sense so, I'll go with the arbitrary 20 over and just hope I don't catch Johnny law in a bad day.

We complain about crappy drivers and the need for better drivers training etc. but, the stats appear to suggest the roads are safer.

I guess as long as you know the lay of the land, just live with it.

Unless you can find a bureaucrat that will make changes that make sense instead of money.


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