The other side of the street looks well treed/shrubbed. It would have been extremely difficult to observe this vehicle unless you heard it drive up.
Where is nosey Nelly when you need her?
If I lived in Austin, it would be a long time before I bought any nails.
It was only about an hour between dark time and this explosion went off. IF it was placed yesterday and not some earlier date. Hope the cops question those bike guys intensively to make sure they are victims and not bombers.
I was wrong. It’s still daylight though headed to twilight at almost 8 pm. That tightens a possible timeline, if it was planted that evening in the dark, to half an hour.