News   GLOBAL  |  Apr 02, 2020
 8.9K     0 
News   GLOBAL  |  Apr 01, 2020
 40K     0 
News   GLOBAL  |  Apr 01, 2020
 5.1K     0 

Ah yes, that Brockville curve is another one!

It's been a while since I've had to design one, but can't you reduce the radius somewhat and increase the superelevation? Or is that already at the limit at 650?

number I gave you was for .06m/m super elevation for 120km/h. I don't think .08 is ever used in Canada for that high of a speed.

The thing with design speed is that it provides the minimum requirements for things like curves, grades, ditches, etc. Often, a segment of highway will not have any aspects that are as low as the design speed. The 401 is not made up of a series of 650m curves, there are straight portions where the design speed for that portion may be well above 130.

The solution is to lower the legal speed at a few critical locations. Nobody says the entire 401 needs to have the same speed. For example, 403 through Hamilton is 90 (or was it 80), while the other parts are 100. The 401 could be 120, with some small segments slower.

I am glad railways do not operate as some describe in this thread, otherwise they would have speed limits for the entire province dictated by one bad curve.

Also function of the geological features of the road. Since new highways are rarely built anymore, you follow what it was designed for.
Having segments different posted speeds is a good idea, but MTO has to look at the potential liability

The road grip of the wide 2015 wheels are much better than the road grip of the narrow "bike-wheel" style 1915 tires. Also, downforce is greater, given to the way cars are more aerodynamically designed.

Another problem... our winters and our occasionally-crooked highway surfaces. Our roadbeds only half as thick as they make it on Germans' Autobahn (almost a full meter thick of aggregate, layers and stuff)

Downforce and thicker wheels do not affect centrifugal force, if you are taking a curve to fast, you will feel as if you are falling out of it, As designers we can mitigate this by super elevating the highway. But because we are in Canada, we can only super-elevate to a certain slope, we have to keep in mind that somedays operating speed will be 120km/h and somedays it'll be 50km/h. If we put too much super elevation, on the days the highway because snowy and 50km/h the car will start to slide towards the center of the circle. (curve)

As for Aggregate, I'm currently working on a highway that recommended 1.5m of granular aggregate. I'm not sure what's typical of 401 (I start a 401 job in the new year), but I have seen in places where they put at least 4 lifts of asphalt. Remember the the aggregate is a much as a base course and it is a drainage course. It's also big reason why pipes burst in the winter, It's not because the contents of the pipe froze, it's the aggregates around the pipe that are not draining loose water, freeze/thaw and shift the pipe enough to burst.
 
In Germany's Autobahn, it's a factor. Minor it may be (compared to racetracks), but a factor, nontheless.

They bank the curves there much better than we do.

Also, one could slightly bank (tilt) the brockville curve to make it much safer at higher speeds. There's some really good banked curves on the Autobahn freeway. 130kph is quite safely navigable in Germany on the brockville radius if running at Autobahn-freeway-quality standards with the traction, quality of roadbed, and banking. I've seen some rather interesting banked curves on some of the better U.S. freeways. Not necessarily to raise the speed limit, but render safer the accidental 130kph overspeeds through Brockville (during a "120kph upgrade elsewhere" situation) in a mitigation measure, even if "90 kph" signs are posted at Brockville. Very prudent safety move. Obviously, not too much banking, since that disorients drivers, but there seems to be almost no bank at all at Brockville compared to other top-notch freeways that was forced to have one sharp radius for one reason or another. They certainly can do better at Brockville, based on what's out there in other countries. What's the maximum banking allowable for Canada's freeways? It's probably tiny, based on what I've seen elsewhere.

The issue with superelevating (banking) that curve (in addition to what I stated above) is that you have off-ramps going either way, designing a transition like that in really difficult, let alone a safe transition, then constructing it. That's even before you worry about drainage, which is more of a driving factor then anyone thinks.
 
The issue with superelevating (banking) that curve (in addition to what I stated above) is that you have off-ramps going either way, designing a transition like that in really difficult, let alone a safe transition, then constructing it. That's even before you worry about drainage, which is more of a driving factor then anyone thinks.
Yeah, I didn't say it would be cheap or easy (e.g. relocating the ramps, factoring for drainage). But easier than expropriating land for a new radius.

Realistically, they'd do nothing, maybe put up a few flashing lights and a changeable-message sign, to alert the drivers of the dangers of the Brockville Curve, if they sped up the rest of the freeway...

In theory, if they did raise speed limits for the rest of the 401.
Which they won't.
As our 401 isn't safely Autobahn material even in the rural straightways. :rolleyes:
 
What I would like to see in terms of speed limits is weather/time of day dependant variable speed limits on 400-series highways. Most rural areas would be 130 on a sunny day with clear roads, 120 at night, 110 in a light rain, with limits dropping to 70 or 80 during dangerous conditions like a snowstorm. The speed limit should actually represent the maximum safe driving speed on that road at that time, not a politically-motivated flat rate at all times.

At this point, I'd like the Province to institute two pilot project areas to test variable speed limits to see if, in Ontario, there is any change in the accident and fatality rates if the limits are raised. The two sections that I would recommend are the 401 between Milton and Kitchener, and the 401 between Courtice and Cobourg. They're both relatively straight and flat stretches, and have 3 lanes in each direction for that entire stretch. Raise the speed limit to 130 (for sunny days with clear roads), but begin enforcement at 135 or 140.
 
What I would like to see in terms of speed limits is weather/time of day dependant variable speed limits on 400-series highways. Most rural areas would be 130 on a sunny day with clear roads, 120 at night, 110 in a light rain, with limits dropping to 70 or 80 during dangerous conditions like a snowstorm. The speed limit should actually represent the maximum safe driving speed on that road at that time, not a politically-motivated flat rate at all times.

At this point, I'd like the Province to institute two pilot project areas to test variable speed limits to see if, in Ontario, there is any change in the accident and fatality rates if the limits are raised. The two sections that I would recommend are the 401 between Milton and Kitchener, and the 401 between Courtice and Cobourg. They're both relatively straight and flat stretches, and have 3 lanes in each direction for that entire stretch. Raise the speed limit to 130 (for sunny days with clear roads), but begin enforcement at 135 or 140.

Pilot project would be a good idea, but the idea of raising the speed limits just to see if there is any accidents or fatalities is a terrible one. There is soo much liability to try something just to see if people die. Something any government wouldn't want to risk. The best defense has been (and always will be) 'we designed it to standards at or above the posted limit'

MTO has accident/injury rates, which they also use as an assessment tool on if a highway needs to be upgraded. I looked at the PDF not to long ago, but can't remember where I put it.

The jest of the document is that MTO considers death valued at 1.5m, so if a highway requires 10m worth of work to make it safer, they will be more likely to do the work on a segment of a highway that has 5 deaths, than 1 death. There is other rates for everything from injury to just property damage.
 
What I would like to see in terms of speed limits is weather/time of day dependant variable speed limits on 400-series highways. Most rural areas would be 130 on a sunny day with clear roads, 120 at night, 110 in a light rain, with limits dropping to 70 or 80 during dangerous conditions like a snowstorm. The speed limit should actually represent the maximum safe driving speed on that road at that time, not a politically-motivated flat rate at all times.

At this point, I'd like the Province to institute two pilot project areas to test variable speed limits to see if, in Ontario, there is any change in the accident and fatality rates if the limits are raised. The two sections that I would recommend are the 401 between Milton and Kitchener, and the 401 between Courtice and Cobourg. They're both relatively straight and flat stretches, and have 3 lanes in each direction for that entire stretch. Raise the speed limit to 130 (for sunny days with clear roads), but begin enforcement at 135 or 140.

I'm with you on the variable/dynamic speed limits according to time of day, weather and perhaps also traffic congestion if possible, but not the pilot projects. The design speed of existing highways is irrelevant as long as most people don't have the driving skill to handle their vehicles at higher than current speeds (speed limit plus a margin of 10-20 km/h). If completely new highways were built to a higher design speed, that might make it feasible, but not guaranteed.
 
Does anyone know if Quebec actually implemented adjustable speed limits in that province?

From this link:

Variable speed limits in Quebec expected this fall


Government to launch pilot projects on 2 Quebec highways


Quebec's transport minister plans to launch a pilot project this fall on two of Quebec's highways to test out variable speed limits.

The speed limit on most Quebec highways is currently 100 km/h. A variable speed limit would mean potentially increasing it to 120 km/h during times when weather conditions permit.

“My intention is to have two pilot projects,†said Transport Minister Robert Poëti, adding that one project would be on a highway near Montreal and the other near Quebec City.

Poëti said the variable speed limits will likely be tested on two roads where the current speed limit is lower than 100 km/h.

"We're going to use that on a lower type of road where sometimes it looks like a highway but it’s not," Poëti said.

Not everyone thinks introducing variable speed limits is a good idea.

“One word — insane. We're in Quebec, people don't obey the posted speed limits," said truck driver Jeffrey Davison.

This month, British Columbia raised the speed limit to 120 km/h on some highways, despite warnings from police that it will increase the risk of serious crashes.

New photo radar system

The government is also looking into a new type of photo radar system.

It involves snapping a photo of a driver's licence plate at the beginning and end of a section of road to see if drivers are arriving too quickly.

If so, drivers could get a ticket in the mail for speeding.

“A similar system exists in Europe and we want to look into the possibility of establishing it in Quebec as well,†Poëti said.

Ontario is falling so far behind other jurisdictions, when it comes to traffic laws & signs.
 
Ontario is falling so far behind other jurisdictions, when it comes to traffic laws & signs.

This doesn't just apply to traffic, but alot of other stuff.

This Ontario government is too concerned about getting federal involvement than taking the lead on things. A CBC interview this morning with Eric Hoskins (Health and Long Term care) taking about strategies for making prescription medication cheaper for low income families.

He called for a national strategy (purchasing program) to make it cheaper, while earlier in the interview praised Saskatchewan's program (and how it saved the province money)
When the interviewer asked why don't we just go ahead and implement this if it's going to save us money? MP kept referring for the 'need' for federal involvement. Even though other provinces have implemented this without federal involvement. Anyways, that's just an example and likely deserves a thread of it's own.
 
Meanwhile, Missouri is thinking about their rural speed limit from 70 mph (113 km/h) to 75 mph (120 km/h). We still can't (legally) go over 100 km/h.

From this link:

Will Missouri become the next state to increase top highway speeds?


Steve Bruns drives a lot — whether long commutes, monthly drives to Urbana, Ill., or a periodic trip to Houston to visit family.

Bruns, of St. Charles, says he’s a “big fan†of the rural interstate speed limits in Oklahoma and Texas, which top out at 75 mph and 85 mph, respectively. Back home in Missouri, the rural limit is still 70 mph outside heavily populated areas.

A Missouri lawmaker wants to change that. State Rep. Mike Kelley has introduced a measure seeking to increase the top speed on Missouri’s rural interstates and freeways to 75 mph.

“I would gladly accept that,†Bruns said in an interview.

Kelley, R-Lamar, said 17 other states — including neighboring Oklahoma and Kansas — already allow people to scoot along rural interstates at 75 mph or higher, and he thinks Missouri could handle the increase. It’s the latest nudge to increase top rural interstate speeds at a time when traffic fatalities are falling.

He said he already sees people driving 75 mph on Interstate 44, which passes through his district.

“I think there is a point where people feel safe, and that is what they are going to drive no matter what the speed limit is,†Kelley said. “We have come to a point on interstates that that is the speed most people travel.â€

If he’s successful, Missouri would join 13 other states — including Illinois — that have increased rural speed limits on interstate highways since 2005. (Illinois went to 70 from 65 one year ago.) Kelley introduced similar legislation last year, but it wasn’t successful.

Gary Biller, president of the National Motorists Association, agrees with Kelly’s observation about human nature. States that have done their own traffic surveys, he said, found that the average motorist on rural interstates drives in the low to mid-70 mph range, regardless of the posted speed.

“It kind of indicates that drivers don’t usually pay a whole lot of attention to the number posted on the sign,†he said.

Still, there are enough drivers who consciously stick to the posted speeds that it creates potential conflict points between the majority and those traveling slower than the prevailing speed, Biller said.

“That differential in speed is what causes conflicts and potentially accidents,†he said.

Biller said the top speed should be based on sound engineering. On highways, that means basing it on the 85th percentile of free-flowing traffic, his group says.

Jason Hoffmann, of Kansas City, drives Interstate 70 to and from the St. Louis area “pretty frequently†and said adding 5 mph to the top speed on rural reaches wouldn’t improve things much without an additional traffic lane.

“There are just too many trucks, many of which make abrupt lane changes, for a raised speed limit to do any good,†said Hoffmann. Nonetheless, he supports the idea of making the limit 75.

Missouri and other states have seen some of the lowest traffic fatality rates in generations. Biller and others note that deaths declined despite speed limit increases. He credits factors such as improvements in vehicles, roads and emergency care.

But some safety advocates argue against higher speeds, warning of reduced driver reaction time, longer braking distances and higher energy forces when crashes do occur.

“States have been falling over themselves to raise speed limits,†said Russ Rader, spokesman for the Insurance Institute for Highway Safety. “No state legislator I am aware of has introduced companion legislation to repeal the law of physics.â€

Studies consistently show that when speed increases on a stretch of road, so too does the number of traffic fatalities, Rader said. By comparison, when top speeds are reduced, the number of fatalities goes down.

Rader agrees that law-abiding motorists already have calculated how fast they can travel without getting a ticket: usually 1 mph to 5 mph over the posted speed. He said increasing the speed limit will push them into a higher speed bracket.

During the 1970s, a national energy crisis prompted the federal government to set a national 55 mph speed limit to hold down gasoline consumption. That top speed remained in place until the late 1980s when it was eased to 65 mph. It was repealed in 1995.

Dan Hyatt, of Maryland Heights, a computer engineer who is familiar with tenets of traffic engineering and Missouri traffic laws, said he believes that higher speed limits would have a marginal effect on gas mileage with today’s cars.

Hyatt added that cars rolling off the assembly line now can better handle higher speeds safely and have features that improve the odds of surviving a collision. He’s in favor of top limits of 75 mph to 80 mph on rural interstates, and 65 mph in the cities.

There’s one more positive side effect, he added. “If you have higher speed limits and don’t have predatory policing, people will drive through Missouri,†he said. “And if they drive through Missouri, they will spend money.â€

Maybe they’ll even fill up at a Missouri gas station, Hyatt said. Taxes from those gas sales are put back into Missouri’s highway system.
 

I'm not surprised it's lower. I recall when the 407 opened there was hand-wringing because it didn't come close to the minimum standards of an Ontario highway. The shoulders were too narrow, or in some places non existent, there were miles with no guardrails along the side of the road, and in some spots no extra protective barriers at bridges or overhead signs. The Burlington terminus was a disastrous design that caused several serious accidents before it was reconfigured. There was also the matter of the OPP not having been contracted to patrol it so for the first few months it was essentially a free for all to drive as fast as you wanted, and people did.
 
Last edited:
I'm not surprised it's lower. I recall when the 407 opened there was hand-wringing because it didn't come close to the minimum standards of an Ontario highway.
It did meet the minimum standards of the MTO. That was the problem. It only met the minimum standards. MTO had been requiring that anyone who designed a highway for them did far better than the minimum, but were too disorganized to change the manual to reflect standard practice, rather than minimum practice.

That being said, I don't think that any of the issues related to lane width, curve radii, or superelevation, so speed shouldn't be an issue for the 407.
 
is it just the parts of the 407 not built by MTO that are an issue? the central portion is great to drive on, and is probably the highest standard road in the province. Its only the parts east of Markham road and west of the 403 that were built by Cintra and not MTO, right?
 
Where is the "Brockville Curve"? I've driven that section of 401 many times but I can't picture where you're talking about.

I hope the speed limit stays at 100 km/h; as a hypermiler, I know that fuel consumption rises sharply with speed. Most people don't care about fuel consumption, though - but if they did, the world would be a much cleaner place, and we'd all have more money in our pockets, too.
 

Back
Top