-- example input to the road network simulator

intersection a nostop 1 -- a cul-de-sac allowing vehicles to wander for a while
road a a 1

intersection b stoplight 1 5 -- test a stop light
road a b 1
road b a 1

intersection c source 10 10 1 -- spit some vehicles into b
road c b 1

intersection d sink -- all the vehicles arrive here eventually
road b d 1