The whole checkpoint idea is scaremongering. Any real threats of terrorism? No, probably not. There are rules around checkpoints and Supreme Court cases. I would be interested to know if anyone refused to open their trunk and what happened. Scattershot 'terrorism' checkpoints have not yet been litigated, but drugs and alcohol checkpoints have. from the drugs article: O’Connor wrote that the same logic does not apply with drug roadblocks. “If this case were to rest on such a high level of generality, there would be little check on the authorities’ ability to construct roadblocks for almost any conceivable law enforcement purpose,” the opinion said. I'd argue the same thing with these 'terrorism' checkpoints. Say no (politely) and ask to be let on your way.