The immediate area around the cars is well lit being at the base of a functional lamp post. Beyond the cone of light extending about a 15m radius, the night is deep. This particular portion of the road is elevated above an area flooded after the Twins. It is not clear how deep the water is, but there are several island hilltops in the area, including the tall one that Sammy indicates is the place the magical attacks came from, which is over a hundred meters away, but has a commanding view of the area. The nearest offramp is about half a kilometer back, though the roads are more boat launch than effective means of egress.
The sniper was apparently positioned on the roadway ahead, which is a relatively straight shot for the next couple of kilometers The chest high median between the opposing lanes making an excellent firing position. O'Conner's firearms knowledge tells you that the median range of a sniper rifle is 150-350 meters.
For all you know the drones could have been satellite controlled. All in all, a pretty nice little killbox you landed in.
An additional note about the area, the I-5 portion that you are driving on is usually pretty vacant at this time of night, the next major community to the south is San Diego, beyond the border. That border between Aztlan and the PCC is not a busy one at high traffic hours, you will probably not see more than a dozen vehicles on this road before the sun comes up, many hours from now.
