One of the most reliable backups inside the Loop right now is the PM reverse-commute inbound on 59. In the early afternoon, when most of the Transtar map is green, the Shepherd-Spur segment is yellow. By the height of the rush, the queue extends at least to Buffalo Speedway. This happens for a number of reasons – but first, the fix. Because it’s ridiculously simple.
Move the diverge point to Shepherd.
To see why, here’s 59 in Greenway. Five lanes. Now here’s 59 entering Midtown, a couple miles further to the east. Again, five lanes – and about to lose two of them.
So add a couple miles of barrier and put the split (“gore point” in traffic engineer speak) at Shepherd. If you’ve driven this route once, you can see how it would immediately shave several minutes off the trip to Downtown/Midtown/Montrose. The Spur is never jammed in the reverse direction, so anything that effectively lengthens the Spur lengthens the distance of hassle-free 60mph cruising. But such a configuration would also help drivers continuing on 59. Here’s why.
Why does 59 back up?
In short, three tailbacks and a weave. 59 through Midtown consists of three lanes which split into three freeways, and backups on any of these are telegraphed through onto the mainlines. The splits:
(i) The two left lanes head to 45. While there is a predictable queue to get onto the Pierce Elevated, it rarely backs up onto 59.
(ii) The two right lanes head to the Eastex Freeway, continuing as 59. This is a more common location for congestion, as there are two lanes coming off 59 and two lanes coming off 288, which narrow to three past the GRB.
(iii) An auxiliary lane gets picked up from San Jacinto which peels off onto 288 after a few hundred feet. 288 South is often backed up, and any tailback from 288 will cause the weave from San Jac to break down, effectively taking out two lanes. This by itself is sufficient to back up 59 past Shepherd, even if both the Eastex and the ramps to 45 are relatively clear.
Even when all three destination freeways are running smoothly, the short weave from San Jac still causes a reduction in capacity – a “bottleneck” if you will – from the theoretical maximum capacity that is available through Midtown.
How does moving the Spur diverge point westward help this? Well, the thing to understand is that the Spur merge acts as a repeater for the Midtown bottleneck. In a normal traffic bottleneck you have three zones. You have the bottleneck itself, you have a queueing section where traffic stacks up waiting to get through the bottleneck, and then you have a free flow section upstream of there.
As traffic backs up on 59 past the Spur, drivers are faced with a dilemma. Do I sit and queue here in the right three lanes, which aren’t moving? Or do I get over and zoom past until right before the split? Many, understandably, choose the latter. But what this does is create a new bottleneck at the point where the Spur diverges, because traffic is merging into the left lane and then trying to cross over to get to 288 or stay on 59.
Now, you may ask, wouldn’t a Shepherd Spur Split just move the repeater point to Greenway? No, for two reasons. First, a lot of the time the backup from 288/59/45 will never make it to Shepherd. Cars will happily (or not) queue up in the right three barrier-separated lanes, and the end of the queue will be somewhere between Midtown and Shepherd. And when it does make it back there, it still won’t be as bad, because Greenway has auxiliary lanes.
Check out the ramp from Kirby. That’s a genuine bonafide lane add, and it merges back in a bit past Woodhead. Engineers put the lane-add there to handle traffic merging from Kirby and Shepherd, but a four-lane section is a four-lane section and that same temporary capacity increase is also ideally positioned to handle the sort of people who stay in the Spur lanes until the last minute. If it were up to me, I’d actually reconfigure the merge at Woodhead so that the left lane drops and the right auxiliary lane becomes a through lane. F-ing Miracles.
I can think of two.
(1) “The lanes will be too narrow!” No they won’t. First, the HOV lane east of Shepherd is extra wide, with 8-10′ shoulders on both sides. Most of the rest of the Houston HOV network is much narrower, so you should be able to gank a few feet from here. Second, 59 in this area has the TxDOT standard 12′ left shoulder. But for a three-lane section, AASHTO only requires 4′, with 10′ “recommended.” And everyone agrees that only 4′ left is required for a two lane section. So where your old cross section was:
30′ HOV – 2′ barrier – 12′ shoulder – 60′ lanes (5×12) – 10′ shoulder
Your new cross-section is:
22′ HOV – 2′ barrier – 4′ shoulder – 24′ lanes (2×12) – 10′ shoulder’ – 2′ barrier – 4′ shoulder – 36′ lanes (3×12) – 10′ shoulder
This obviously requires a couple meetings at the TxDOT level, but the Feds would rubberstamp it.
(2) “You’re cutting off Shepherd’s access to the spur!” Okay, valid point. But how important is Shepherd-Spur traffic in the grand scheme of things? Anyone getting on and off there has there choice of a myriad different east-west arterials, including Westheimer, Alabama, Richmond, and even Memorial/Allen. Sure, in an ideal scenario you’d add a flyover to route Shepherd/Kirby traffic to the Spur. We’re still in a liquidity trap, and I have an aesthetic appreciation for concrete, so I’m not the type of person to disparage dropping a couple million on a flyover of questionable virtue. However, given the choice between (i) forcing local trips to take local streets for an extra mile and a half, and (ii) shortening the commute times for the other tens of thousands of people who reverse-commute on 59 each day, I don’t think it’s really a contest.
Start the Spur at Shepherd.