I’m wondering why MODOT/St.Louis County Decided not to convert the CD exit-roads and Hanley into a SPUI (Single Point Urban Interchange)?

Just looking at Hanley and the exit Roads, that combined intersectionlooks a lot liek the intersection at Page and I-170, which gets congested.

Traffic backing up into the bridge intersections are never good, and SPUI’s like that at Olive and I-170 do a good job of eliminating that. The setup scenario seems to be the same - allowing long left turns and longe green times.

Any thoughts, Ms. Crouch?

In response to Kwame — I’ve heard that the single-point interchange idea isn’t doable due to lack of space there. Here’s the answer from the county, from David Wrone, spokesman for the highway department:

“Our primary goal, when analyzing Hanley and Eager roads, was to reduce the number of vehicles moving through this interchange. Development of a Single Point Intersection would have left insufficient land for our Jug-handle. Without the Jug-handle, traffic volume would have remained more or less at pre-improvement levels in this area - with tens of thousands of vehicles coalescing there from I-64/40, Eager, Dale and both directions of Hanley every day. Thus, we chose the Jug-handle design - which will greatly dilute the numbers of motor vehicles passing through Hanley at Eager (or vice versa).”

I’m not sure why the fuss over how southbound Hanley will connect to westbound Eager, it’s clearly displayed in the diagram. The only possple issue will be when the eastbound Eager to southbound Hanley drivers, and the southbound Hanley to westbound Eager drivers, cross paths in the small space between Hwy. 40 and Dale.

I agree with John’s 8:23a, 8/2 post. The ONLY fly in the ointment seems to be a tedious exercise in lane crossing for SB Hanley Drivers, who need to take a right on Dale, to go WB on Eager, WHILE EB 64 “Exit Road” drivers are just headed SB, WHILE EB Eager drivers are also trying to head SB… Two sets of volume heaed SB, while another set is desparately trying to get on Dale to go WB on Eager? Is there a better word than “tedious”?

Bob G. provided a great visual link and why I don’t think their is no good solution here that can satisfy everybody. The culprit is that lack of planning has allowed box store development run amok with all traffic directed to Eager. Look at all the box stores and surface parking that are built like little fiefdoms on the map in the link

My suggestion for Brentwood/Richmond Heights and the county that would promote future development and better land use is a cut through blvd by extending Dale Ave from Hanley, over the metrotracks, and onto Brentwood parallel Eager. Then reconnect the streets from the Hanley business park to this new mini blvd. This would allow better vehicle, metrolink and pedesterian access. You would have a very strong area for mixed use development from retail, office, residential, and light office if a street grid could be re-introduced to this mess.

Ok people. I’ve said it before, and so have the traffic engineers (and for the same reasons), but a single point interchange won’t work there. I will however humor you. Just so you can have an immediate image of why this won’t work, here is a great animated image of one.

http://www.3dnworld.com/users/35/images/hntbhighway.jpg

Do you see the problem? For the CD roads to function like they’re supposed to, traffic has to be able to flow STRAIGHT THROUGH the interchange. While this works with diamond interchanges, this does NOT work with single point interchanges. This means that once everything is said and done, WB 40 traffic will not be able to get to Brentwood via the north CD road, and traffic from Brentwood will not be able to access EB 40 from the south CD road. These problems will effectively make both CD roads worthless. With this route, they may as well have also designed Brentwood and 40 as a single point and just forgotten about the CD roads, but with the interchange of a major freeway right inbetween Brentwood and Hanley, it would have ultimately resolved nothing, even if both interchages were single points and therefore able to move high volumes of traffic quickly. That way, there would just be too much traffic and it would bottleneck there just like it always has. They designed it the way they did for a reason (i.e. builing two more roads for traffic instead of just redesigning interchages). Like I said though, I’ll humor those of you who want it. Firstly, if you want a single point interchange at Hanley, the jughandle has to go. Bye, bye. Secondly, traffic has to be able to flow straight through that interchange somehow. My solution: put a one lane bridge that will be in the middle of the CD road (there will obviously be one for each road) and cut right through the middle of the “Y” and that will take traffic over Hanley stop light free. However, there will be blind corners all over that bridge as a result of this, the project budget will have to increase by SEVERAL (bold, italicized, highlighted, underlined, hyperlinked!) million to cover the cost of these two small bridges, and access to Eager will HAVE to go back to its original design. Now, I thought of this idea in a bit of an “off” moment and I know something like this will N E V E R be built because it’s profoundly retarded (not to offend) and way too expensive. I humored you guys though. By the way, if you tell this to a traffic engineer, they will laugh at you, tell you you’re crazy…..and then hang up the phone.