Houston: I-10 San Jacinto River bridge replacement

[MaxConcrete]

Related thread: https://www.aaroads.com/forum/index.php?topic=25712.0. However, since this post is not about the barge collision, I'm starting a new thread for the new bridge.

A public meeting was held today for the new bridge.
https://www.txdot.gov/projects/hearings-meetings/houston/i10-sjr-091923.html

Observations

• The planned new bridge is 5-2M-2M-5, and is 6-2M-2M-6 if the entrance/exit lanes on the bridge are included. (M=managed lane). The existing bridge is 3x3.
• All new right of way is on the south side, which is the downstream side and is not at risk for barge strikes.
• The schematic shows a 1.3-mile-long elevated structure, which is about half a mile longer than the current bridge elevated structure.
• At the San Jacinto River crossing, the new bridge will have a vertical clearance of 52 feet and a 386-foot clear span over the shipping channel. The graphics in the presentation suggest the actual span may be a little longer. The existing clearance is 23 feet vertical and 158 foot horizontal. The new vertical clearance is below the standard Intracoastal Waterway clearance, which is 73 feet.
• The main span will be a steel beam design. The video says numerous designs were considered and steel beam was selected.
• While it's good to see TxDOT thinking long term by including the managed lanes, I'm inclined to wonder if it really makes sense to build them now. TxDOT's long-term plan for I-10 east is to add managed lanes, presumably all the way to downtown Houston if possible. But that would be in the very far future. NHHIP is currently scheduled to be completed in 2042. I don't think there would be any other work on I-10 east until after NHHIP is complete. Realistically, we're probably looking at the 2050s for any major work on I-10 east to add more managed lanes. Maybe the managed lanes are viewed as an alternate or emergency facility if either the eastbound or westbound lanes needs to be closed.
• I think this project is the highest-priority project in the planning phase in the Houston region. The presentation says construction is scheduled to start in winter 2027. Construction cost is estimated to be $555 million.

[Chris]

No frontage roads are included in the plan. In some other areas of Texas, they are spending quite a bit of money to remove gaps in the frontage road system. Maybe an 18 lane bridge is a bit oversized for this location.

At the San Jacinto River crossing, the new bridge will have a vertical clearance of 52 feet and a 386-foot clear span over the shipping channel. The graphics in the presentation suggest the actual span may be a little longer.

This appears to be common for bridges over waterways, where the physical dimensions (span length, height) are bigger than the navigational dimensions.




For reference:

[longhorn]

Let me guess, build the east bound span first, demo the old one. Build the managed lanes in old east bound right of way, move westbound on to it temporarily. Demo westbound span, rebuild it. traffic keeps flowing..............supposedly.

[rte66man]

Related thread: https://www.aaroads.com/forum/index.php?topic=25712.0. However, since this post is not about the barge collision, I'm starting a new thread for the new bridge.

A public meeting was held today for the new bridge.
https://www.txdot.gov/projects/hearings-meetings/houston/i10-sjr-091923.html

Observations

• All new right of way is on the south side, which is the downstream side and is not at risk for barge strikes.

I would strenuously disagree with this statement. The I-40 Webbers Falls bridge collapse was triggered by a barge headed upstream. If they do not account for upstream collisions, they will be culpable when, not if, there is a collision.