That’s because it’s not “signal priority”, it’s “timed signals” where the timing is triggered by the entry of a train into a station. This is the same system they use on Max north of Lombard and east of 181st. And you’re right, if the train gets a little late (usually because someone holds the door at a station or a wheelchair ramp has to be retracted — that may not be germane for Link) then the train is repeatedly stabbed until the next station when the cycle is reset.

Signal priority advances or retards the signals for cross streets in realtime response to the presence of a train.

I think it’s obvious that Link should be above/below grade whenever possible.

I don’t think you can make blanket statements like this. It really depends on the exact at-grade configuration (some allow full-speed running and don’t require trains to wait for cars), ridership, and how much of a regional feeder the line will be. For example you might want to have a fully grade-separated trunk line splitting into mixed traffic street-running branch lines such as Muni, MBTA Green Line, or SEPTA Subway-Surface lines.

Remember often the choice is between running at-grade or no rail at all. Lets not let the perfect be the enemy of the good enough. If we’d required MLK to be fully grade separated it likely would not have been built at all.

I took Link the other day to Tukwila for the first time in months and we stopped at EVERY SINGLE red light.

That is more of a problem with how the signal priority system works and less one with at-grade operations in general.

Would Microsoft contributing to improved light rail service in Bellevue really be a bad thing? If so, why?

Or, more generally, are we better off for not having advertising/private concessions/etc as part of our public systems?

Another example, not transit related, are the public toilets that Seattle rolled out, and then rolled back in again. My understanding is that part of the reason Seattle failed with these (as opposed to San Francisco) was that we paid for everything with public funds (as opposed to advertisers covering most or all of the costs).

Would the tunnel be a possible candidate for such funding?

The issue is that when a train is stopped at the station, the only buses that can move will be the ones at the last bay on the side by the train which can depart and one entering the first bay on that side. Buses already in the middle and first bay can not depart and buses destined for the middle and last bay can not enter.

When the train is entering or leaving the station they will probably all be instructed to wait, for safety.

It won’t work.

Once Link is extended, delays in that section will slow the entire region down. We need to avoid that mistake in the future.

If we can’t tunnel we should either find more funding, elevate it, or use the BNSF corridor. Link should not be at grade and should not be at the mercy of traffic lights!