RE: "Never see red light"
but it will be interesting to see how close they get to this ideal.
I don't think this is 100% achievable when trains run in opposite directions on the same road,
This was a problem in Melbourne, and in San Diego, where one of them, I forget which, had to back away from total priority, as the problems with vehicular delay were to be expected, what wasn't expected was that oncoming tram/trolley timing was negatively affected in many cases. It was concluded that in practice, unless the tracks were run separately 'off-road', giving both directions of travel 'full priority' through road intersections was next to impossible. A working compromise had to be found and was, and that involved the 'occasional red light'. Needless to say, state of the art control and dispatch systems optimize the throughput.
I'll try and find the study, and post the relevant section.
Edit to Add: This points to some of the research I'm looking to quote:
Melbourne trams may never have to stop at traffic lights, under VicRoads plan
By Marissa Calligeros
Updated13 February 2015 — 11:28amfirst published at 10:20am
[...]
"Trams already get significant priority at traffic signals. The biggest challenge for Melbourne is tram routes that share the road with other vehicles. The delays are not due to traffic signals, but rather the queue of vehicles ahead of them."
For the past seven years, VicRoads has been working with researchers at the University of Melbourne and Monash University to determine how changing traffic conditions, including traffic light frequency, might ease congestion in the city.
The research team has used mathematical modelling to test alternative ways to run the network.
Mr Wall said the research focused on developing ways to maximise the number of people moving around the transport network, rather than the number of vehicles.
The study also examined the restriction of on-road parking with clearway zones.
It found that there was only a real benefit in restricting on-road parking within 100 metres of intersections.
With Melbourne's population expected to reach about 8 million by 2053, Mr Wall said the roads authority had to explore new congestion management methods.
Mr Wall said mathematics was being used in a similar way in European countries including Germany and Switzerland, because it was a cheap and effective alternative to traditional forms of modelling.
[...]
https://www.theage.com.au/national/...ghts-under-vicroads-plan-20150213-13dnwo.html
Note that transit is a state competence in Oz, which assists greatly in the "Capital Cities" (Code for all major Oz cities) being at the forefront of railed transit. This means that Toronto's "King Street Pilot" would be under aegis of the Transport Ministry, and funded by same. What a topic that would be for the beleaguered King...
This may be more to the point, albeit dated:
The Design of Tram Priority at Traffic Signals
https://onlinelibrary.wiley.com/doi/pdf/10.1002/atr.5670190204
K/W Ion is unique, as mentioned by various posters, in the "vertical and horizontal white bar" signals, an interesting subject in itself. I'm still trying to track down the Provincial sign-off on allowing that, as the Highway Act only allows for the vertical one, something wholly pertinent to the Toronto King Street Pilot (albeit the Highway Act has a section on allowing the Minister complete carte-blanche to allow "pilots" any device they may wish as the Minister's discretion for some ten years or so.)(last section of the Act)
In Ion's case, some of that might even be federal under the Transportation Act, as some of the Ion signals conform to, and it is shared running with a federally regulated spur. Whether they share Ottawa's OC-Transpo Transport Canada dispensation or not is a good question.
That horn, btw, is almost identical to the TO Flexity ones, if not the same. In Ion's case, I think a railroad type might be more effective, if allowable, at least initially. And a clanging bell. It's got to be something to strike a degree of fear into errant motorists.
I've found the San Diego Trolley experience, different study than I remember, but same observations and findings:
TRANSPORTATION RESEARCH RECORD 1361 Trolley Priority on Signalized Arterials in Downtown San Diego STEPHEN CELNIKER AND E. WAYNE TERRY
[...]
The previous preemption system was unable to accommodate the increased amount of preemption pulses initiated by trains traveling in opposite directions simultaneously. Because the preemption timing could serve trolley movement in one direction only, the trolley traveling in the opposite direction would be stopped by red lights at nearly every signal. Sometimes several trolley preemptions would be entered in rapid succession, creating significant delays for cross traffic and pedestrians as the signals departed from normal operation for several minutes at a time. In a few cases the signals received so many preemption pulses that the equipment malfunctioned, locking up with red lights in all directions, serving neither motorists nor pedestrians nor trolleys. The success of the trolley had overwhelmed the preemption system that had been designed to serve it.
TROLLEY PRIORITY SYSTEM The solution to the preemption problem was technically quite simple. Rather than requiring the trolley to alter the normal operation of the traffic signals to receive favorable timing, instead have the normal operation itself favor the trolley. By favoring the trolley, the system proved more effective for all users because it was time-fixed and more reliable. This concept became the basis of the trolley priority system, which was implemented in 1990 in a cooperative effort between the city of San Diego and San Diego Trolley, Inc.
The system works as follows:
• The trolley dwells in the trolley station until the beginning of the next green light at the first downstream signal.
• The trolley departs within 5 sec of the beginning of the green light.
• If the departure window is missed, the trolley must wait until the beginning of the next green light.
• As long as the trolley leaves the station during the departure window, the trolley will receive green lights at all of the signals until it reaches the next station.
• The two-phase, fixed-time signal timing favorable to the trolley is always in place and is fitted into the larger network of signals. For a time-space diagram illustrating an example of progressive timing for the trolley, see Figure 2.
[...]
http://onlinepubs.trb.org/Onlinepubs/trr/1992/1361/1361-027.pdf
