Maximum light rail drive on sight speed in North America

Germany's street railway and light rail construction and operating ordinance sets 43.5mph as the highest speed limit on drive-on-sight trackage for light rail and for buses on rails. This is less than the speeds at which similar sized heavy road vehicles are driven on freeways and these, of course are driven on sight. For reference on size, a classic twin bogie streetcar is about the size of a bus that is also not articulated.
Most systems in other European countries also follow the German standard. But what is the standard in North America?

50-55 mph is a common limit.

So how come it is higher in North America? A lot of things are generally larger (houses, stores, passenger cars, trains, streets, etc) and that apparently includes light rail vehicles. If they are generally heavier, then then braking distances would be greater at a given speed.

Don't know the history, but there are generally 2 maximum speeds in North America for rail transit, either 50-55mph or 70-75mph. The 70-75mph is usually for subway type for those systems willing to have extra maintenance and energy costs or have very long runs. Braking effort is specified generally at service braking max of 3-3.5mph/s squared independent of car weight, so a 60K pound car has same braking distance as 80k pound vehicle.

I think first of all, a better understanding of what you mean by "drive on sight" - do you mean operating on shared rights of way (i.e. pure street running or center median with frequent grade crossings), or do you mean on private right of way either with no block signaling at all, or signals that are not enforced by some kind of automatic speed/train control system?

Also, keep in mind that "North America" is quite broad too - regulations vary wildly between the United States versus Canada versus Mexico, and in the case of the US, even between states, agencies, etc.

OK, so let's look at the first assumption - street running. That one's easy, generally a light rail line would adhere to the civil speed limit of the road it's running on, although in practice they'd probably run a little slower and with caution because LRVs are comparatively big and people + automobiles = idiots. The traffic lights perform the role of a "signal system". With a reserved side-of-road or center median ROW, speeds might be higher if the ROW is adequately fenced and grade crossings protected by lights/gates/etc.

Otherwise with private ROW but no signal system (rare but not unheard of, looking at you MBTA Mattapan Line) or with a signal system but no ATC enforcement (a lot of those exist), I don't think there is any maximum speed standard or rule at least in the US. Speeds would be based on infrastructure and operating conditions, and in the case of no signals at all there would probably be something in the rule book that says "run at a speed that will always allow you to stop before hitting anything in front of you". I know APTA and FTA have some guidelines and recommended practices but not sure of any hard, unviolable speed limit rules that apply to all properties. Then again I'm not in the light rail biz, so don't take that as gospel.

I am aware on railroads (a much more standardized environment) there are hard, federally-established limits on how fast you can go in "dark territory" versus with basic block signals versus full ATC.

DART in Dallas, on very rare occasions, reaches speeds up to 65 mph. Most of the time, light rail speeds are less than 45 mph. DART does not run at these high speeds on streets/ Higher speeds occur in ex-railroad right of ways.
There is a youtuber who has recent cab view videos up with and without GPS data on the screen for every DART line.
Here's the link to his web site. https://www.youtube.com/@VideoGuy_TX

If, say signals are only at junctions, such as crossovers, and give no indication of whether the line ahead is clear, that is drive-on-sight, block signalling does give indication of the state of the line ahead. When sharing a road with manually steered vehicles, they must be driven on sight. The traffic lights at intersections do not tell drivers if the road ahead (on the other side of the intersection in the direction they are heading) is clear, I don't believe that would work if directed at drivers who have to steer.

The Eglinton Crosstown line in Toronto will operate at 60km/h at grade - the City passed a bylaw to permit that section speed because the road limit is 50km/h. The grade crossings are not gate protected which may be a factor but Metrolinx may have also merely said that with stop spacing and all trains making all stops, 60km/h is as much as they need.

Okay but is it line-of-sight or block working?

I don’t think it’s block working, at least on the long surface portion between Science Center Station and Kennedy Station Portal. But I haven’t been along that portion of the line since test vehicles started running on it

Myrtone wrote:Germany's street railway and light rail construction and operating ordinance sets 43.5mph as the highest speed limit on drive-on-sight trackage for light rail and for buses on rails

I believe on TriMet MAX the highest speed outside of ATC is 35 MPH (56 Km/H); in ATC territory it is 55 MPH (88.5 Km/H). The 35 MPH speed limit would be comparable to motor vehicles travelling on East Burnside or North Interstate where MAX runs in the median. Once MAX is on its own ROW (and gains block signalling), the speeds increase.

Of course in downtown Portland where MAX shares space with other vehicles (including privately operated, non-transit vehicles in some places), the speed limit is even lower.

What about the Tiajuana trolly?

The interurban type lines with long open stretches have higher speeds, such as Riverside (D) Line and the 101
Media Line which can hit 50.

The interurban type lines with long open stretches have higher speeds, such as Riverside (D) Line and the 101
Media Line which can hit 50.

Besides, are there any other lines?