In case anyone decides (like me yesterday) to park at the Addicks Park and Ride and start at the THP extension that crosses under I-10. Don't do it. Big sign at the entrance. Effective April 1 the trail is closed for dam construction until 2019.
Then I found that Park Row is now open all the way to Eldridge and beyond (via Dairy Ashford). Unfortunately it blocks the THP extension and there are solid Armco barriers on both sides of the road. Maybe they will elevate the trail over Park Row at some point. I ended up driving to the parking lot off the I-10 feeder and starting there.
Thanks Sci Guy for mentioning the Mason Creek bike trails. I rode out to Fry and then found the link up by the elementary school and did some exploring. Pretty cool trail with a lot of pedestrian bridges over Mason Creek. I ended up getting nearly 40 miles. It was fun day off. I haven't been that way in quite a while.