I'm confused why he even would have been on that road to begin with? These are both routes from Texas State to Missouri City. The street view of the road he was on reminds me of "typical" Texas "country roads." They usually have no street lights and would be incredibly dark at night.
ETA: the Salt Flat Road runs between the first two routes. both would require toll if he were trying to avoid that.
Just googling, it looks like if he maybe took the TX 142E route through Lockhart, he would have been right in the Salt Flat Rd. area on his way to 183/I-10 connection to Houston. A longer route by 10 minutes but probably more populated. I'm in the Austin area. I'm very familiar with 183 and I-10 to Houston but not Tx 142. I just hope he's found safe.