u3: allocate emergency buffer on every road, free on bail for trace cells
u3: allocate emergency buffer on every road, free on bail for trace cells

(cherry picked from commit 3a11a08b712b52805f97ceb06da8417a8b7cbde4)

urbit/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit