Totally Tubular on I-170

After more than six month of dangerous conditions on I-170 near Eager Road, MoDOT has finally taken some action, though some might consider it a bit extreme.

Back in July, I documented the dangers of an interstate with just a double yellow line separating traffic. This year, things only got worse. If you are southbound on I-170 and want to continue to Eager Road, you steer left of the concrete barrier, right next to oncoming traffic north on I-170. This has resulted in at least a couple of reports of wrong way traffic on the west-to-north flyover ramp.

Tubular MarkerMy recommendation was simple. Line the tenth of a mile of 2-way traffic with tubular markers (shown at the right), similar to those on Hanley at Dale/Eager,. Simple and space-saving. Instead, Gateway Constructors and MoDOT decided to shutdown northbound I-170 traffic from Eager Road. Here’s their explanation:

Though north and southbound I-170 traffic has been in a similar configuration since May without incident, the recent opening of the south to east flyover ramp moved the Eager exit to the left lane, while the center and right lanes took the flyover ramp to eastbound I-64. The design was safe and there have been no major incidents, but the public concern for a change has driven this decision.

C’mon. It’s safe, there’s no incidents, but “public concern” resulted in the change? How can wrong-way drivers on an interstate be considered safe? If it was really safe, there wouldn’t be a need to shut down the northbound lane. It’s not safe, but MoDOT and Gateway Constructors won’t admit it.

What impact will this shutdown have on traffic? Normally, I’d say that this would cause a traffic mess, since the only way to get on northbound I-170 from Hanley is to cut across Eager, north on Brentwood, then get on I-170 at Galleria Parkway. However, if there’s one thing I’ve learned since January 2nd it’s that traffic jams are awfully hard to come by. Many of the alternative routes are actually at the same or lower volumes than before the shutdown. Go figure.

My Preschooler Can Draw Better Lines

I bet MoDOT never expected the I-44 restriping project to be one of the stickiest situations so far in the Highway 40/I-64 construction project. First were the concerns about the safety of moving from four lanes to five. Then, the project was delayed from a scheduled completion of November 1st (as reported by the Kirkwood-Webster Times) to still not being done 10 days before the Highway 40 shutdown. Finally is the fiasco of the actual restriping itself — I drove I-44 to downtown on Monday, and it was frightening: vanishing lane lines, wide lanes, and a sudden move from five lanes to three near the I-55 merge. As expected, MoDOT said the situations were temporary and due in part to the recent weather. However, 6 days later, I still found many problems with the restriping.

The glare from the sun on the camera might magnify the problem, but I can assure you that the lane lines were quite difficult to see at times. MoDOT needs to do the following:

  • Finish the restriping — this includes the missing right lane line on eastbound I-44, and all the ramps.
  • Repaint all the faded lines — this needs to last for two years and the current condition is unacceptable. If the weather’s too cold, then perhaps they should get out there with blowtorches. That’s what I saw in New Jersey last week as road workers there used blowtorches to dry the roads in preparation for painting during cold, wet weather
  • Regrind out the old lines — in too many places, the old lane lines still appear white. They need to be ground out again.

If MoDOT expects I-44 to take up the most traffic from the Highway 40 shutdown, then they need to get this restriping right. And the “temporary situation” excuse won’t cut it. If someone’s in an accident due to these poor lane lines, they won’t care if the situation was there for a day or a year. If it isn’t safe, it needs to be fixed immediately.

Are Narrow Lanes on I-44 and I-70 Safe?

In preparation for the Highway 40/I-64 shutdown this January, MO-DOT is in the process of restriping I-44 and I-70, a process which will add an additional lane for the anticipated alternate route traffic from the shutdown. The Post-Dispatch covered the topic in an article today. What caught my eye, though, was this section:

Officials say there’s no evidence that the narrower lanes will increase the number of traffic crashes.

“We haven’t seen any difference in the accident statistics,” said Linda Wilson, spokeswoman for the Transportation Department. “We aren’t aware of any research that shows statistically more accidents.”

Really? I did a quick Google search for “narrow lane accident rate”. The second item on the list was a study from the U.S Department Transportation on how adding a lane on an urban highway affects accident rates. It’s key finding:

The analysis results indicate that narrow-lane or shoulder-use-lane projects on urban freeways increase accident frequencies for four- to five-lane conversion projects.

(from: “Safety Effects of Using Narrow Lanes and Shoulder-Use Lanes to Increase the Capacity of Urban Freeways“)

Now, as with any study, there are a lot of details. I sorted through the discussion on Empirical Bayes Analysis and statistically significant results. The above results are statistically significant. The only caveat is that many projects in the study added a High Occupancy Vehicle (HOV) lane as part of the project, which could contribute to the accident rate, though that was not analyzed specifically.

Furthermore, the study postulates that “downstream” traffic may also have increased traffic rates. An example of this in St. Louis would be eastbound I-44 which will be restriped to have 5 lanes. Near the I-55 junction, though, those 5 lanes get reduced to just 2. That junction may prove to be more accident-prone according to the study.

So, a 10 minute Google search by a non-traffic engineer turns up a study showing statistically more accidents when lanes are narrowed on urban highways. Yet MoDOT couldn’t find such evidence? Did they really look, or was it more convenient to state that their actions are safe? I don’t expect a MoDOT spokesperson to be thoroughly read on all the latest traffic engineering studies. But I do expect that MoDOT employs traffic engineers who do read these studies and who consider those studies when making traffic changes.

Featured on Fox 2 News in the Morning (Updated)

Highway 40 Insight was featured on Fox 2 News in the Morning today. John and Randi had a good time with my favorite posting: Lane Shifts and the Loss of Common Sense.

Update 8/2:

John and Randi from Fox 2 interviewed me this morning about the web site and, particularly, the videos on the site (lane shift video, double yellow line video). We were a bit rushed due to coverage of the tragic bridge collapse in Minneapolis. Still, it was a fun experience and hopefully got the message out to a few more drivers to be careful in the construction zones.

Worker killed on Highway 40

I’m sure many of you have seen the tragic news of Gavin Donohue, the college student/summer construction intern who was killed on Highway 40 in Chesterfield over the weekend. He was working for Pace Construction, not as part of the major Highway 40 rebuilding but on a repaving project. Let’s hope that some good can come from his death, in that all drivers strive to eliminate injuries and death in our area construction zones. The lives of drivers and construction workers are not an equitable trade for getting home from the Cardinals game a few minutes faster.

Full coverage:

Double Yellow Line Danger on I-170 (Updated)

In a previous post, we saw how the lane shift at Tamm avenue caused drivers to wander out of their lanes. At least they were all going in the same direction. Recent changes on I-170 near Highway 40 have resulted in two way traffic separated by just a double yellow line. Let’s see how drivers handle this situation:

In the few minutes I watched traffic at I-170 and Galleria Parkway, nearly 50% of cars in the outside lane touched or crossed the dashed white line. Fewer crossed the double yellow line, but it only takes one car to do it at the wrong time before you have a serious head-on collision (like this crossover accident on I-64 in Illinois this week). It seems that southbound drivers are approaching this area too quickly to negotiate the lane shift to the right without wandering out of their lanes.

Median Crossover GuidelinesI looked at the federal guidelines to see what they specify for such a situation. Although these guidelines are always subject to interpretation, the guidance I found would recommend use of channelizing devices instead of just the double yellow line. The figure to the right shows the guidance for median crossover on a freeway. It specifies as a standard “Channelizing devices or temporary traffic barriers shall be used to separate opposing vehicular traffic.”

Another section of the federal guidelines addresses a similar situation to I-170, but just for a total of two lanes:

When two-lane, two-way traffic control must be maintained on one roadway of a normally divided highway, opposing vehicular traffic shall be separated with either temporary traffic barriers (concrete safety-shape or approved alternate) or with channelizing devices throughout the length of the two-way operation. The use of markings and complementary signing, by themselves, shall not be used.

Tubular channelizing deviceBased on what I’ve seen at I-170, I would recommend avoiding this section of roadway until some sort of channelizing device is put into place to separate opposing traffic. The device shown at the right could be put in place with little impact on spacing. If you are concerned about this section of roadway, share a comment here, but, most importantly, let the I-64 construction team know by leaving them a comment on their web site. I will be.

Update 07/06/07:

The team at was once again prompt and professional in their response to my concerns about this section of I-170. Here’s what they had to say:

The area you describe is not a typical interstate construction zone. The freeway currently ends and begins at Eager Rd. In the current construction configuration, it operates as a typical 4-lane arterial roadway, with the double yellow line separating the north- and south-bound traffic. Traffic in this area is posted with a workzone speed limit of 45 mph. Vehicles in this section are approaching a stop or just leaving from a stop, so the interstate standards are not relevant. A channelizing device is not required for that type of roadway condition.

I agree that northbound traffic is leaving a stop and is more cautious going through this construction zone. However, it’s the southbound I-170 drivers that think they’re on a interstate when they enter this construction zone. That area around Galleria Parkway sees high speed southbound drivers, and I do think that some channelizing device would reduce the risk of a head-on collision.

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