[CDL.TO]

Economists, actually.

So you're saying that Traffic Engineers, who actually plan this work and the associated contingency plans, don't actually know about induced demand? That they can't say that traffic didn't all migrate elsewhere?

 

[Woodbridge_Heights]

It's possible, if people are coming from North of Queen st., and depending on their destination that people may have simply chosen a route North on Spadina rather than South. I know on occasion when heading North-West that taking Spadina North to Dupont/Davenport to Keele to Black Creek Drive was often as fast or faster than a congested route south to the Gardiner.

 

[Tuscani01]

Contrary to what someone else said earlier, I did notice that a lot of the traffic just switched to Bathurst. Front Street was always backed up westbound to Bathurst from Spadina during the closure (Which is unusual), along with being backed up Eastbound towards Spadina. I guess people who needed the Gardiner would take Bathurst to Front to Spadina... while those who would just go to Lakeshore just used Bathurst right down, which caused Westbound traffic on Front to back up, as Bathurst was busier than usual with everyone avoiding Spadina/Queen.

My condo faces Front Street, so I see how traffic flows on a daily basis along Front, Spadina and Bathurst.

 

[sixrings]

This exact same happened when they shut down the ALLEN expressway northbound ramp for three weeks in the spring. Eglinton had alot less traffic and people found other ways out of the city. Made me think the ALLEN wasnt as necessary as some people would make you believe.

 

[k10ery]

So you're saying that Traffic Engineers, who actually plan this work and the associated contingency plans, don't actually know about induced demand? That they can't say that traffic didn't all migrate elsewhere?

I just meant that it is an economic idea not an engineering one - the resource of public highways cannot be managed efficiently, as long as it is free to use.

I don't know much about what's taught in civil engineering programs, so can't say who knew what when. But the induced demand paradox is named after economists Pigou and Knight (who did most of their work 1910-1940) and political scientist/economist Downs (did most of his work 1950-70). Traffic engineers were clearly widening expressways for a long time after these guys had written down the induced demand idea.

 

[CDL.TO]

I just meant that it is an economic idea not an engineering one - the resource of public highways cannot be managed efficiently, as long as it is free to use.

I don't know much about what's taught in civil engineering programs, so can't say who knew what when. But the induced demand paradox is named after economists Pigou and Knight (who did most of their work 1910-1940) and political scientist/economist Downs (did most of his work 1950-70). Traffic engineers were clearly widening expressways for a long time after these guys had written down the induced demand idea.

That's fair enough. I just don't think it's fair to suggest that even in 2012 that people who work in transportation still don't understand this. There is a wealth of literature on the subject coming from the engineering and planning fields as well. Sadly, many are slow to clue in (including economists).

 

[BurlOak]

This exact same happened when they shut down the ALLEN expressway northbound ramp for three weeks in the spring. Eglinton had alot less traffic and people found other ways out of the city. Made me think the ALLEN wasnt as necessary as some people would make you believe.

Eglinton may have been less crowded, but the surrounding streets may have been more crowded.

 

[k10ery]

Ah good link. I've heard the theory of course, but I've never actually seen references to the original work.

It does reinforce, that the only way in a city like Toronto to improve driving commutes, is to build more rapid transit.

Or, better, to toll the expressways at rush hour.

 

[k10ery]

That's fair enough. I just don't think it's fair to suggest that even in 2012 that people who work in transportation still don't understand this. There is a wealth of literature on the subject coming from the engineering and planning fields as well. Sadly, many are slow to clue in (including economists).

Absolutely, I didn't mean to suggest engineers don't now get it - Toronto traffic planners (not politicians) obviously do. Engineers have the first hand experience and the data. But they may not be that good at modelling what is basically a social not physical phenomenon. Here's the best recent study I know - by economists. (Bad news for nfitz in there, by the way.)

 

[nfitz]

Or, better, to toll the expressways at rush hour.

Better yet! It would make it so much easier to drive then.

Here's the best recent study I know - by economists. (Bad news for nfitz in there, by the way.)

Interesting. And probably not surprising. If you get induced from adding capacity, then it shouldn't really matter if the capacity added is because of expansion, or them changing modes. Hardly bad news, it is what it is.

Road tolls it is then!

 

[Dan416]

Ah good link. I've heard the theory of course, but I've never actually seen references to the original work.

It does reinforce, that the only way in a city like Toronto to improve driving commutes, is to build more rapid transit.

If only. Toronto seems to love to plan to build rapid transit without actually building anything.

At least TYSSE and the Eglinton line are underway.

 

[k10ery]

Interesting. And probably not surprising. If you get induced from adding capacity, then it shouldn't really matter if the capacity added is because of expansion, or them changing modes. Hardly bad news, it is what it is.

Good point. If you can't toll, the next best thing for road congestion is to reduce public transit travel times. It's speed and convenience of the alternative that matter - not the impact on road VKT.

 

[doady]

If only. Toronto seems to love to plan to build rapid transit without actually building anything.

At least TYSSE and the Eglinton line are underway.

Toronto currently does not have any rapid transit planned or under construction other than the Spadina subway extension.

 

[nfitz]

Toronto currently does not have any rapid transit planned or under construction other than the Spadina subway extension.

The section of the Eglinton line currently under construction, which is grade separated and will have speeds the same as our existing subway lines isn't rapid transit? Right ...

 

[Kitsune]

All that traffic has gone to Simcoe... it's been backed up from Lakeshore to Wellington every Evening ever since they shut down Spadina/Queen... and even with the re-opening it's still clogged.