[lightrail123]

You are factually incorrect here.

It's grade separated pretty much all the way north to Northgate and beyond. (Which opened this year.) Northgate, Roosevelt, U District, UW, capitol Hill, all the downtown stops are all separated in tunnels/elevated rail.

It's at grade only in parts of SODO and South Seattle. The bulk is separated. Even when not, it takes priority at crossings and has it's own lanes that are rarely shared with cars.