How safe is this tunnel for families?

It's a underground bridge. I suggest that you drive under instead of walking. The lighting inside is very dim. However, you can see the drawings from the outside. Alot of traffic traveling under the bridge.

I wouldn't walk through at night and I would be cautious during the day with small kids if a lot of spray painting is going on. The fumes can be oppressive. It's a great thing to see though!

Daylight, good except for the taggers. Spray paint fumes BAD. Night is not for....

very from what i can tell... had no issues

I agree. I took my family during the day. Ate at the market then walked around taking in the sights

I have been there for photo shoots day and night, as with any place, make sure you have a buddy and watch for the traffic.

I wouldn't wander after dark but in daylight I've walked through many times with no issues at all. Do be mindful of the cars though.

Daytime, totally. I haven't been there at night.