Are you growing any fennel nearby?* Fennel can cause other plants to bolt.* See the companion planting recommendations as well as bad combos at these sites.
As far as the light from the street lights, I would think that would cause more growth and larger plants more quickly.* At least that is what happens in Alaska with their long days.* I would be more concerned with the potential pollution in the soil from the cars.* Have you had a soil test done?
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.