When you're trying to run quality transit in a mixed-traffic situation, and you have a street with two lanes of traffic in each direction, the best practice is for transit to run in the faster lane, the one further from the sidewalk. We see this most commonly with streetcars, but it's true of any mode of street-running transit. That's because the lane closer to the curb is often delayed by random car movements, including cars turning, or trying to parallel-park, or doing pickup and dropoff. So long as the fast lane is separate from any turning lanes, it's the lane where you'll get the best travel time in mixed traffic.
But of course this is a speed vs access tradeoff, because it means people have to cross the slower lane of traffic to get to the transit vehicle.
So how do riders get to it safely, as pedestrians, when there's a lane of traffic in the way?
I've seen three solutions:
1. Create a boarding island for stops in the fast lane, with controlled crossings of the outer lane. Melbourne, for example:
The problem with these standard New World models is that the transit stop is clearly a separate place from the sidewalk, so that when you get off the transit vehicle, you're not really "there" yet. The separation also discourages people from just boarding a vehicle spontaneously when they see it coming.
2. Create a "mixed" space where drivers get a clear message to slow down. In a Vienna example that I observed but wasn't able to photograph, the streetcar in the fast lane is at the same height as the sidewalk, while the curb lane between them rises up to that height just in the stop area; traffic engineers call this a "table," and it has many other applications as a traffic calming device.
Even the dullest motorist will sense this bump upward as indicating they're entering a space that's not just a through-way for themselves. The disadvantage of this is that motorists have to go over this bump whether there's a transit vehicle there or not.
3. Create a special signal, behind the transit stop, that simply stops the curb lane of traffic when a vehicle is loading or unloading. This method is common in Berlin. In this image, the car in the curb lane is stopped by a signal that you can see (facing away from us) just above it. The signal turned red in response to the streetcar's presence.
(0. Number 0, because it's not a solution, is to make no provision for the pedestrian crossing at all. San Francisco's California Street cable car, for example, has several intersections where the cable car stops in the fast lane and the signal tells gives motorists a green light to run over the people getting off. At least it still did when I was last on that street earlier this decade; can anyone send me a photo of how it works at, say, California & Hyde today?)
Now that I've watched the Vienna and Berlin examples in action, and both work really well, I suspect that the prevalent North American and Australian solution -- Option 1, the boarding island -- may reflect some old traffic engineering values and may not be the way of the future. I'm sure a manual will tell you that it's theoretically safest, because pedestrian traffic is officially channeled into signalized crossings. It's also the least sensitive to spontaneity, and sends a counterproductive message that the transit service is something separate from the pedestrian life of the street. I tend toward Option 3, the transit-activated signal that simply stops the curb lane of traffic.
What do you think? Are there other options?