Norristown, Pennsylvania Speed Traps

No cop car seen, just looks like a fender bender from a distance. Then a cop walks into street points to a person & has them pull over right before the intersection of New Hope & E Fornance Streets.
Trap set up in early moning while people are going to work. Set up on a road that (as far as I have seen in 5 years of living there) has not had 1 regular police car stop a motorist. Speed is 25 but is not a small road so it is not followed. Average speed on that road is 30-40 mph.