Dear Matthew Alice,

The Coronado Bridge is an imposing structure, admittedly, and is pretty hard to ignore. That’s why I was wondering why in the dickens the lights were blazing away on it the other day, in the middle of the day. Surely it wasn’t so some battleship wouldn’t run into it. It’s bad enough that we have to pay $1.20 every time we want to cross it — now we’re wasting our tax dollars lighting the thing up during the day. Why?

Concerned Citizen

Coronado

I suppose the answer would be that it’s too expense to pay electricians to work at night. Or perhaps it’s that they do what they do better (or more safely) during the daytime. Either way, the bridge was ablaze with light the other day so that electricians could see which bulbs needed replacing.

Lighting the way across the 2.5-mile span are approximately 200 yellow sodium vapor lamps — bright, fancy, expensive bulbs, to be sure, but light bulbs nevertheless. And light bulbs need to be replaced, of course, except for the one up in a fire station in northern California that’s supposedly been burning since 1901. The bulbs on the bridge need replacing more often, about every two years. So periodically the lights are switched on, the electricians go out on the deck, and any burned-out or feeble bulbs are replaced. Makes a much nicer post card (“Coronado Bridge by night”) if all the lights work, instead of having blank spaces, don’t you think?

And by the way, the lights are governed by a photoelectric cell that switches them on when the light level falls below a certain point in the evening (or during an eclipse) and off after the sun comes up. If it gets foggy, the lights can be turned on manually from the toll plaza.