Unfortunately, the bridge is only open late one week per year as part of National Bike Week.

There are definitely events on the Camden waterfront that would be much more accessible if the bridge is open late. The cynic in me says that PATCO doesn't really care about keeping the walkway open late because they don't make money on walkers, unlike the "Hi Speed Line" or the bridge tolls. But realistically, I'm sure that "desirable" bridge traffic decreases quite rapidly as it gets dark, making the costs for patrolling hard to justify.