Which is more effective for better transit? Signal Priority or Dedicated ROW?

[Mapleson]

I've voted Neither/Other, as I believe a grade-seperated Right of Way is more effective than either signal priority or an at-grade deticated Right of Way.

Without signal prioritization, a deticated Right of Way has limited effectiveness. Similarly, signal prioritization in mixed traffic is limited by congestion. So long as we aren't including cost in the defination of effective, grade-seperation beats both hands down.

 

[gweed123]

I've voted Neither/Other, as I believe a grade-seperated Right of Way is more effective than either signal priority or an at-grade deticated Right of Way.

Without signal prioritization, a deticated Right of Way has limited effectiveness. Similarly, signal prioritization in mixed traffic is limited by congestion. So long as we aren't including cost in the defination of effective, grade-seperation beats both hands down.

Agree 100%. However, most of the conversation here has been in the realm of smaller improvements, as opposed to full grade separation.

Personally I see it as sort of a progression in terms of the 'intensity' of transit (I don't know if that's the right word to use, but I'm going to go with it anyways):

Mixed traffic -> Queue jump lanes/signal priority -> Dedicated ROW -> Grade separation at major intersections -> Full grade separation

 

[mpd618]

There's two very different ways of considering what constitutes a bigger transit improvement. The first is how much it improves transit trip times. The second is how much it improves transit trip time relative to auto travel time for the same trip.

Beyond reducing the number of stops and dwell times, and increasing frequency, I believe you need some form of dedicated right-of-way to improve relative transit performance.

 

[reaperexpress]

I would tend to debate that. Urban arterials are much more prone to crawling along than suburban arterials are. Queen Street crawls along at pretty much all daylight hours. Outside of rush hour, a street like Bayview flows pretty well. The delay on suburban arterials happens when an arterial meets another arterial, and they both require long complicated light cycles. If buses can get queue jump and signal priority at these locations, it would do wonders for their efficiency.

I guess what I'm saying is where is the gridlock located. If it's just at intersections, signal priority and queue jump lanes are better. If it's along the entire stretch of roadway, dedicated lanes are better.

Queen street crawls along at all times of the day, but it is by no means gridlocked. Suburban arterials flow very nicely for much of the day, but at rush hour they become undeniably clogged.

For a concrete example, we could compare Queen street with Dufferin Street between Finch and Steeles. Both streets have two lanes per direction, but Dufferin carries more cars. So Dufferin is more limited by the physical capacity of the road, while Queen is more slowed by the traffic lights.

It's true that arterial intersections are the source of suburban gridlock, but once triggered, the roads quickly reach their critical level of usage and queues become enormous.

For example, Dufferin and Steeles is the pinch point for northbound traffic, but the queue on Dufferin often stretches most of the way to Finch. So a "queue jump" lane would have to be nearly 2km long to skip the lineup for this traffic light, and at that length, we might as well call it a dedicated ROW.

 

[kEiThZ]

A dedicated right-of-way is always more effective for transit.

Is it always cost-effective? That's the more important question.

 

[reaperexpress]

A dedicated right-of-way is always more effective for transit.

Debateable.

Case in point: Lakeshore Avenue West in Etobicoke.

There's hardly any traffic anyway, and putting in a ROW would actually slow down streetcars, because it would reduce green time on lakeshore by requiring separate left turn phases. To make matters worse, when there is an advance left in one direction only, cars can proceed but streetcars cannot.

The fastest option option would be to relocate the streetcar tracks to make room for left turn lanes, while providing signal priority.

 

[kEiThZ]

^ I was thinking something a la Ottawa Transitway, York busway, etc.

But even in your example, that has to do with how cars are managed. The ROW would still be faster than having the streetcars in mixed traffic....

 

[reaperexpress]

^ I was thinking something a la Ottawa Transitway, York busway, etc.

But even in your example, that has to do with how cars are managed. The ROW would still be faster than having the streetcars in mixed traffic....

Yes, if it were an independant ROW like those busways, it would be faster, but if it were a median ROW it would not.

 

[sixrings]

ROW will always be quicker then in mixed traffic... PLus I would think iots better since once its in its hard to rip out... Priority lighting can always be changed back. Thats a HUGE factor when you live in a car oriented city.

 

[leopetr]

Depends.

In low traffic and infrequent service, signal priority can be effective.

In high traffic and frequent service, ROW is more effective.

 

[gweed123]

Depends.

In low traffic and infrequent service, signal priority can be effective.

In high traffic and frequent service, ROW is more effective.

ROW is always more effective. The debate is really when ROW is more COST effective.

 

[reaperexpress]

If ROWs are "always better", than why is the Bathurst streetcar just as fast as the Spadina streetcar, why is the 506 Carlton the fastest streetcar route, and why are streetcars so damn slow on Queens Quay?

 

[doady]

If ROWs are "always better", than why is the Bathurst streetcar just as fast as the Spadina streetcar, why is the 506 Carlton the fastest streetcar route, and why are streetcars so damn slow on Queens Quay?

Spadina does carry two times the amount of passengers. Could Bathurst carry 48,000 riders and still be faster than Spadina? Probably not.

506 Carlton might be fastest due to Carlton having less congestion? Congestion does seem to be a factor in the speed of transit operating in mixed traffic. Maybe Carlton is less congested.

When Mississauga Transit implement signal priority on 19 Hurontario a few years ago, they found it to be not useful because many of the bus stops on Hurontario were located on the near side of intersection instead of the far side. So obviously the placement of stops is a factor as well.

 

[gweed123]

If ROWs are "always better", than why is the Bathurst streetcar just as fast as the Spadina streetcar, why is the 506 Carlton the fastest streetcar route, and why are streetcars so damn slow on Queens Quay?

External factors independent of ROW or signal priority: stop spacing, light spacing, traffic volumes, passenger volumes.

 

[reaperexpress]

External factors independent of ROW or signal priority: stop spacing, light spacing, traffic volumes, passenger volumes.

That's the point. A streetcar on an uncongested street without a ROW can be faster than a streetcar on a ROW.

In other words, ROW =/= speed.

Which brings me back to my initial point that ROW and Signal priority are just concepts and this poll is pointless. The obvious answer would be "both".