I have had Murphy following me for too long to get away with much.. He steps in when I get cocky like that. I zoomed past a guy once, then had a (back) blowout halfway up the bridge I commute across daily. He passed me and waved as I was pushing it up the arch. (When no one was around I weighed
my bike on the scale at work. It comes in at 84 lbs, as equipped and loaded.)
I haven't had a bad reaction yet, I get a lot of people asking me about it when I go places. Before I motorised it, I used to hate the (e-bike) powered bikes that I encountered because (again, on the bridges) they'll ride up right behind you and sit 6" back and you're trying to pedal up the span. Now when I see an e-bike I usually roar past them, but that's only because they've got a 32 km/h (19.88 mph) governor, and I can easily do double that (and more) WOT. It is. Really.
I get a mix of reactions from drivers, but that's for another thread.
When I see a pedaller is already ahead of me before I get on the bridge, I pull to the side for a couple of minutes and wait until they're near the top of the arch before I start up after them, just so that I don't ride up behind them while going up. I always catch up to them on the downside, but I usually cut the motor at the top and coast down when someone's ahead of me.