What I'd do
I'm certainly no expert on this, but it seems to me that something more could be done at these checkpoints. The reasoning for shooting at cars that don't stop seems completely adequate in the light of suicide bombers driving cars into checkpoints. However, there must be a way to effectively stop a car without bullets a safe distance away. If the avenue of approach is narrow enough I see no reason we couldn't employ remotely activated spike strips in front of the checkpoint. Certainly the avenue of approach could also be narrowed as well using concrete barriers like what are used in construction areas. Any other ideas?