And this isn’t even about scrambles (a.k.a. the Barnes Dance) and diagonal crosswalks.
No, it’s simpler. People walking in different crosswalks aren’t going to crash into each other and hurt or kill themselves. They’re not cars.
However, we treat them that way because people are an afterthought in signal design. Here are two examples from Redmond, WA.
#1: NE 51st St. and 156 Ave NE
A little context: North is up in the image. SR 520 is to the west (hence the slip lane to keep it highway-like), Microsoft and low-rise apartments are to the south, single-family housing and a minor arterial are to the east, and single-family homes and lots of rat running (a story for another time) are to the north.
We’ll concentrate on traffic from the north and south. For car reasons, these are separated into two straight-and-left signals. Traffic from the north goes first, then from the south, and then the east/west phases. Pedestrians are given a green when they can be hit by right-turning but not left-turning cars.
During PM rush hour, there isn’t a lot of car traffic from the north, but sometimes people want to use the crosswalk on the west side of the intersection. When this happens, the car traffic, if it even exists, clears out quickly, but of course there is a long pedestrian count because the intersection is large. During this time, people driving figure out that no cars are moving, and the right-turns-on-red heading to the east begin:
Now there’s a stream of cars making that turn (generally without stopping) when the signal changes, which means that if you’re a person trying to cross on the east side of the intersection, there are cars moving across the crosswalk when you get a green. Or effectively a leading car interval.
Better would be to end the useless car green during the pedestrian crossing is occurring. Then the eastside crossing could overlap with the west side:
Then when the west side crossing is done, the intersection can transition into the normal phase that allows traffic from the south to go. And you get a leading pedestrian interval for free.
#2 W Lake Sammamish Pkwy NE and NE Marymoor Way (Sammamish River Trail crossing)
A little context: North is up in the image. I’ll refer to northwest as north (and so on). North/south is a major arterial. To the east is Marymoor Park, which has light traffic unless there is an event.
There isn’t a marked crosswalk or pedestrian signal across the north side. The south side is matched with turns (but no conflicts!). The east side gets the usual conflict with right turns.
As before, the turn pockets are exhausted before the pedestrian phase is finished (5 lane crossing!), so everyone else sits idle:
Instead, the east side crosswalk could be activated, and again this would give a leading pedestrian interval before the turning traffic starts:
And shouldn’t the major trail be getting priority here anyway?