Widening parts of I-270 and I-64 by reducing lane widths/St. Louis TIGER II

[Revive 755]

http://www.ewgateway.org/pdffiles/boardpackets/2010/boardpacket-June2010.pdf (scroll to Page 12/39 for the TIGER II stuff; the I-270 and I-64 widenings are 1/3 of the way down Page 13/39).

Given how MoDOT was not able to keep the extra lanes created on I-44 and I-70 from reducing the width of the shoulders and existing lanes, I don't see how they would be allowed to do the same on I-270 from I-64 to I-44 and on I-64 from I-270 to MO 141.

That particular section of I-64 has supposedly gotten much worse since the rebuild east of I-270 was completed, and could get even more problematic after the northern half of the MO 141/Maryland Heights Expressway corridor (which will be maybe 80% freeway, 20% expressway) is completed.

As for the other possible TIGER II projects:

* A bike trail for East St. Louis? I really see that one getting a lot of use.

* I-64/22nd Street interchange?  Works fine.  Someone want to redevelop it, let them pay for it out of their pocket.  Much better uses for tax dollars out there than fixing this interchange.

* I-170/Scudder Road interchange:  Need more information on this one, but it ought to be a candidate for closure, given its proximity to the I-170 interchange and the nearby Airport Road interchange.

* Studying I-270 from I-70 to IL 111:  Not sure there's too much a multimodal solution can do here (unless multimodal includes the truck only lanes MoDOT wants); the eastern half of the corridor simply needs to be widened. to a minimum of six lanes.

[edited to fix message icon]

[ShawnP]

Grrrrrrrrr MODOT should lose Interstate status on any Interstate they try to narrow the shoulders and lanes on. All this is doing is inviting accidents with less room for safety.

[Chris]

It's a cheap way to generate some extra capacity, but it doesn't quite add to traffic safety and a robust network. One breakdown or minor accident and the entire freeway + adjacent highways become jammed.

[Revive 755]

Regarding the I-270 planning study from I-70 to IL 111, the audio of the EW Gateway meeting makes it look like the planning project will be dropped from the list.

[Bryant5493]

I-75/85 is pretty narrow through Downtown, which is why thru trucks have to use 285 around the city. Additionally, U.S. 78 between the Stone Mountain Freeway and Scenic Highway/S.R. 124 in Snellville has narrowed lanes, for capacity. It's not the best situation, but it is what it is.


Be well,

Bryant

[Revive 755]

The draft 5-year TIP for the St. Louis MoDOT district is up, the I-270 widening appears on Page 18 or 40/66:
http://www.ewgateway.org/pdffiles/DraftFY2011-2014MoDOTProgram.pdf

The cost seems to have gone up by $2.5 million.

[3467]

How Narrow would the lanes have to be? IDOT narrowed the lanes on the Kennedy through Hunnords Cave at least 20 years ago to add lanes. It is a tunnel under railroads widening would have been impossible otherwise.
The Kennedy lanes look 10 or 11 feet but I am not sure. Maybe someone else does

[Revive 755]

Using Google Earth, the narrowest section of I-270 appears to be 129' edge of pavement to edge of pavement, with 8 12' lanes (96' total), a 10' inner median (including the inner shoulders and jersey barrier), and 2 9' outer shoulders (18' total) - but that only comes up to 124'.  Assuming the lower value, with no pavement widening MoDOT could 10 11' lanes with no outer shoulders and a 4' median.

From past conversations with MoDOT, the main obstacles to normal widening for this stretch of I-270 are the railroad bridges, with a secondary obstacle of needing a lot of blasting in residential areas.

[ShawnP]

It's St. Louis so my recommendation is blast away!

[Chris]

The freeway in my city (Zwolle, Netherlands) has a "temporary" left shoulder running. That lane is no more than 6.5 feet wide (2 freaking meters). So it can always be worse. Most people don't even attempt to drive on it.

[Revive 755]

A little more info on the I-270 and I-64 TIGER II options:

http://www.ewgateway.org/tigerII/opssafety/Appendix_B_I270_from_I44_to_MO100.pdf

http://www.ewgateway.org/tigerII/opssafety/Appendix_C_I64_from_I270_to_MO141.pdf

I would really like to a see a more detailed plan for both of these, but I'm really curious on the ramp reconfigurations for I-64.

In addition, another TIGER II candidate, the I-170/Scudder Road interchange, now seems to include fixing the ramp from EB I-70 to NB I-170 so it will enter I-170 on the right instead of the left:

http://www.ewgateway.org/tigerII/freight/Appendix_D_I-170_Interchange.pdf
(map on bottom of Page 4/17, the ramp and new C-D lane are hard to see)

I kind of dislike the weave this will introduce with EB I-70 to NB I-170 traffic having to cross NB I-170 traffic to Scudder Road; I'd rather see the Scudder exit braided with the WB I-70 to NB I-170 ramp (yeah I know this probably ain't happen with this design due to costs)

[ShawnP]

I recommend no on both projects as they do nothing to improve safety and actually lower it with dangerous driving combinations of weaving and narrower lanes. If this goes thru FHA should subtract said miles from MODOT's Interstate account. You should never lower width standards on Interstate highways unless during construction and only then in extreme circumstances. Narrowing lanes greatly increases accidents and puts added stress on drivers. Shame on MODOT and any other transportation agency or person that put their name on this ingredient for accidents.

[kharvey10]

given MoDOT has pulled it off on the Boone Bridge sometime in the 2000s, its not surprising they're up to their old tricks again.

They were given permission to temporarily do 44 and 70 inside of 270 because of the construction on Highway 40.  They're taking that trick to 364 and 370 when they rebuild the Blanchette.

That damn survey for 270 in North County is not off the table by any means.  MoDOT really wants to upgrade 270 east of 367, but IDiOT is only concerned with replacing the canal bridge with a piece of junk.

[Sykotyk]

No. And God No.

Reducing lane width is devastating to anyone driving anything bigger than a compact. You're just asking for brush-by accidents. Also, it causes vehicles to stagger behind vehicles in adjacent lanes rather than to try and overtake for fear of getting too close.

So, the capacity issue only helps when traffic is near standstill levels where the space is easily navigable.

Sykotyk

[Alps]

Lane widths down to 11 ft are fine for trucks, 10 ft is really the minimum you want on a freeway. You could go to 9 ft if you have almost no trucks on the road, but that's not the case here. (Unless you tell all trucks they HAVE to use other routes if they're over 7 feet wide.)

[Sykotyk]

Lane widths down to 11 ft are fine for trucks, 10 ft is really the minimum you want on a freeway. You could go to 9 ft if you have almost no trucks on the road, but that's not the case here. (Unless you tell all trucks they HAVE to use other routes if they're over 7 feet wide.)

Atlanta does this with the I-285, which would be fine.

As for 11 feet. For an 8'6 wide vehicle with mirrors adding almost another foot, you're giving about 18 inches between passing trucks. At highway speeds, that's greatly unsafe. 12' should be the minimum width for any interstate.

Most cars only 6'6 to 7'6 wide have trouble navigating an 10'-11' wide lane. Trucks would only be more difficult.

[3467]

Most state roads in Illinois were 9 foot until  the late 60s. I recently went by a truck on the other side and we both fit but it was only a 30 mph zone.
The Texas Poor boy 4 lanes are 11 feet and posted 65 with no shoulders.
Studies have shown they are marginally safer than a 2 lane with shoulders and 12 foot lanes

[agentsteel53]

The Texas Poor boy 4 lanes are 11 feet and posted 65 with no shoulders.
Studies have shown they are marginally safer than a 2 lane with shoulders and 12 foot lanes

really??  I would've never thought a narrow four-lane would be safer than a wide two-lane with shoulders.  More efficient, certainly, but safer?  Unless of course people were so fed up with the congestion caused by two-lane striping that they were passing on the shoulders or in the suicide lane and getting into trouble...

[Alps]

Lane widths down to 11 ft are fine for trucks, 10 ft is really the minimum you want on a freeway. You could go to 9 ft if you have almost no trucks on the road, but that's not the case here. (Unless you tell all trucks they HAVE to use other routes if they're over 7 feet wide.)

Atlanta does this with the I-285, which would be fine.

As for 11 feet. For an 8'6 wide vehicle with mirrors adding almost another foot, you're giving about 18 inches between passing trucks. At highway speeds, that's greatly unsafe. 12' should be the minimum width for any interstate.

Most cars only 6'6 to 7'6 wide have trouble navigating an 10'-11' wide lane. Trucks would only be more difficult.

If you said "in my opinion" I wouldn't argue. Fact is, you're wrong. It's not unsafe. Years of operational experience have proven that 11 foot lanes do not dramatically affect either speeds or capacities - read the Highway Capacity Manual. 12' is the standard width. You don't want more than that - then cars start passing each other inside the lanes during congestion and all hell breaks loose. 12' standard, 11' minimum. 10' absolute minimum (in some places, 10'-6") during construction when necessary, but you'd like to avoid that condition. These have all been tried, tested, and proven.

[froggie]

If you said "in my opinion" I wouldn't argue. Fact is, you're wrong. It's not unsafe. Years of operational experience have proven that 11 foot lanes do not dramatically affect either speeds or capacities

On that note, recent research noted at the TRB annual meeting suggests, where the speed limit is 45 or less, there's little difference between 12ft lanes and 10ft lanes.

[3467]

The Texas poor bot study was done by Texas A&M.
My Opiion but I was driving on a 31 foot wide pavement duringa repaving and it had few lane markings. It "felt" like 3 lanes would easily fit there especially with the 5 foot gravel shoulders.
Then the lane markings came back and it "felt" narrower

[Sykotyk]

The Texas Poor boy 4 lanes are 11 feet and posted 65 with no shoulders.
Studies have shown they are marginally safer than a 2 lane with shoulders and 12 foot lanes

really??  I would've never thought a narrow four-lane would be safer than a wide two-lane with shoulders.  More efficient, certainly, but safer?  Unless of course people were so fed up with the congestion caused by two-lane striping that they were passing on the shoulders or in the suicide lane and getting into trouble...

You obviously haven't driven in Texas (at least West Texas).

The general rule is if you're going slower than the person behind you, you ride the shoulder 'lane' and allow the trailer vehicle to pass you in their lane of travel (therefore, rarely needing to actually across the yellow). You can pass this way without worrying about a gap in oncoming traffic. It, essentially, is the poor-mans-four-lane that is used only as needed.

[agentsteel53]

oh, that's what a Texas Poor Boy is??  I had thought of something like a 1930s four-lane, like the main drag in Marfa, Texas, where there are four eleven-foot wide lanes and no shoulders, and each of them is intended to be used by all traffic at all times, with no lane acting as half-shoulder-half-travel-lane.

[agentsteel53]

The general rule is if you're going slower than the person behind you, you ride the shoulder 'lane' and allow the trailer vehicle to pass you in their lane of travel (therefore, rarely needing to actually across the yellow).

also, you apparently haven't driven anywhere on this planet.  I find that maybe 10% of drivers use slow-travel lanes or turnouts when someone is coming up behind them at a greater rate of speed.  90% of people are happy to be a roadblock on wheels.  

just today, someone was doing 30mph in the brutal no-passing stretch of US-395 between Kramer's Junction and Adelanto, holding up traffic for miles.  This is a two-laner with decent enough shoulders that this schmuck could've pulled over at any time and let everyone by.  Therefore, I can only assume his behavior was some sort of elaborate practical joke.

[J N Winkler]

oh, that's what a Texas Poor Boy is??  I had thought of something like a 1930s four-lane, like the main drag in Marfa, Texas, where there are four eleven-foot wide lanes and no shoulders, and each of them is intended to be used by all traffic at all times, with no lane acting as half-shoulder-half-travel-lane.

Nope, the cross-section you describe for the main drag in Marfa is classic poor-boy.  Pulling half onto the shoulder of a two-lane that has full shoulders is simply a courtesy to allow passing.  Other alternatives to the poor-boy configuration include intermittent passing lanes and S2+1 (called "alternating four-lane" by MoDOT, the key idea being that there is always a passing lane in one direction or the other).  The choice among these various cross-sections depends partly on cost and on expectations of future traffic growth.  It is considered uneconomical to provide passing enhancements on a two-lane road if traffic will eventually increase to levels that justify provision of four lanes.

FWIW, Ezra Hauer (curmudgeonly but reliable) has surveyed the evidence on the relationship between safety and unit lane width and found that, from the perspective of safety, the "sweet spot" is between 11' and 12' but actually closer to 11' than 12'.  And of course Steve is correct that the capacity and speed penalty of going from 12' to 11' is minimal.  (I think, however, that the 1965 Blue Book advised designers that capacity of a 10' lane was about 70% that of a 12' lane.)  Eighteen-wheelers and other large trucks have deep cones of invisibility, however, which make these findings prima facie somewhat suspect when truck percentages are high.