Nice graphics, did your team develop that in-house?
Ideas to block roads ...
1) car crashed into corrugated iron work hut and knocked over scaffolding holding uniform grey cement blocks. You could have fun making a mess out of the effect of a smashed block turning into a dust splat.
2) Bus tried to do a U-turn and got stuck in the road, everyone except the driver got out and walked (on the other side of the bus - the doors aren't facing the player)
3) road works
4) building exploded leaving rubble everywhere
5) police have put plastic tape up and stand guarding the road, if you fire your rocket launcher at them - you die.
7) I'm bored, get a copy of hl2 and some of the mods.