My point is that there must be people who aren't involved in criminal gangs or deliveries crossing this bridge, too, so there should be a general interest in keeping it safe.

It seemed like these were targeted attacks- specific time window, specific target group. Most people crossing won't have something worth thousands of dollars on them, which can conveniently act as its own getaway vehicle, and which can then be fenced through what sounded like an established pipeline for this particular item