"Direct Lane" Experiment on I-25 in Denver

[The High Plains Traveler]

From the Denver Post 7/12/14: CDOT is going to try striping the inside lane on southbound I-25 with a double solid line near the C-470/E-470 interchange on the south side of the metro area, Their intent is to encourage through drivers to stay in that lane and leave the other two through lanes open for weaving for drivers maneuvering to either avoid the exit or get over to it. At this interchange, there are three through lanes and three exit lanes with one optional lane. The double line would extend south of the next exit at Lincoln Ave.

We'll see how this works. I have occasion to go through there, often getting on southbound I-25 two exits north of the 470 interchange, and it's sometimes a challenge to move left over the three lanes needed to avoid having to exit.

http://www.denverpost.com/news/ci_26133989/cdot-aims-ease-gridlock-direct-lane-pilot-effort

[usends]

I caught a snippet of this on the radio this morning, and my first thought was, "Great, that means more slow drivers in the passing lane."

[Henry]

I hope I'm wrong, but this is a disaster waiting to happen.

[myosh_tino]

I hope I'm wrong, but this is a disaster waiting to happen.

I don't know.  To me, this is a mini Express/Local setup where the express lane is the far left and other two make up the local lanes.  I-15 through Las Vegas has a similar setup except there are 2 express lanes.

[jeffandnicole]

At least with 2 express lanes you can pass.  If a timid driver gets in the left lane, there's no ability to pass, and by creating a large gap in front, it encourages drivers in the 'local' lanes to (illegally) merge into the left lane.

[The High Plains Traveler]

I expect a lot of lane stripe violations, especially in the beginning. Last Saturday night I came through there and the new signage was up, though covered. One had the cover blown off and I noted it's a relatively small yellow rectangular sign with words to the effect "No Access to E-470/C-470 or Lincoln Ave from Left Lane".

Also, the comments above about slower moving vehicles in the left lane (who really ought to be using the other two lanes, no reason why they can't) are probably valid. By this point on SB I-25, vehicles are beginning to speed up to the 75 mph speed that begins just south of Lincoln.

[1995hoo]

We have something like this on I-66 in Northern Virginia outside the Beltway. Through a couple of interchanges the left lane is set off with a double white line and you aren't supposed to cross it. The idea is mainly that the left lane is a peak-direction HOV lane and the idea is that there is no reason why HOV traffic would need to cross out of the HOV lane, and no reason why there would be HOVs who weren't already in the HOV lane, when you're passing through an interchange. I assume VDOT figures that during the rest of the day the same logic applies–you can't exit, so there is no need to change into or our of the left lane through there.

But the double white line is routinely ignored, especially during non-HOV hours when the left lane is open to all traffic. One reason is the point "jeffandnicole" makes–people in the left lane can't (legally) get around a slower vehicle, and the same applies to people in the leftmost of the lanes to the right of the double white line.

I think if the authorities really want to separate a lane with nobody changing in or out, they either need to give it some spatial separation in the nature of a small culvert (I-84's HOV lane northeast of Hartford comes to mind), use pylons (the HO/T lanes on I-495 in Virginia and I-95 in Miami come to mind), or use a raised barrier like a curb (I-95 in New Jersey near the GW Bridge comes to mind, though traffic there is often so slow people routinely cross over the curbs).

[myosh_tino]

Re: People ignoring double white lines

Tell me about it.  When the I-680 Express Lane opened over the Sunol Grade, cheating was (and to some extent still is) pretty rampant.  Caltrans installed "DO NOT CROSS DOUBLE WHITE LINES" signs but they're so small, it's hard to read at 65 MPH.

[roadfro]

The I-15 Express Lanes in Las Vegas had some issues at first, but people seem to be taking to them now.

The configuration of I-15 in this stretch is a variable length left shoulder (wide enough in some areas for breakdown refuge area), two express lanes, a narrow painted buffer (maybe 2-4 feet wide) with solid wide white stripes, then general travel lanes and shoulder. Press releases and media often refer to the buffer area as "double white lines", but they are in fact two single solid lines.

The express lanes were implemented while the I-15 south design build project was going on in the southern half of the resort corridor (this was the project that built the collector-distributor roads), so there was some confusion at first. Crossovers Once the freeway construction was done, they put in candlestick delineators in the buffer area--this cut down the improper lane changes, but the candlesticks were frequently damaged and littered the highway. After a repaving project, the delineators were removed and they went back to just paint but compliance seems to have kept up as locals got used to the setup.


Long term, the express lanes are planned to be converted to HOV lanes. This will be after Project Neon widens I-15 north of the resort corridor to the Spaghetti Bowl (Sahara Ave north to I-515/US 95/US 93) and constructs a direct flyover to the HOV lanes on US 95.

[mrose]

It's not a terrible idea in theory, but that's a terrible place to use it, IMO, for reasons which have already been expressed.

[1995hoo]

So, anyone have any updates? How is the lane in Denver working?

[Milepost61]

I haven't had a reason to drive through there yet so nothing to report. Haven't heard anything on the radio or newspaper about it one way or the other since it was implemented.

CDOT set a one month pilot period for it so I guess we'll see if they leave it in place after that.

[Zmapper]

I drove through in the lane last week at around 1 pm. Compliance was relatively high; only one or two cars visibly changed lanes in front of me.

As it isn't safety critical to have local and express traffic absolutely separated, I wouldn't worry about the occasional violator that occurs with only double-white lines and spot enforcement. I would be more concerned about a driver causing a collision by being unwilling to drive over flex posts in an emergency. Double-white lines are failsafe in the sense that people would be more willing to drive over them if necessary.

[jakeroot]

^^^
What is the context of that conversation? It doesn't seem in-keeping with the "direct lane" we are discussing.

[roadfro]

Zmapper's comments are discussing the safety ramifications of drivers violating the barrier between express lane and general purpose lanes. Particularly, is it less safe for drivers to illegally cross the separation consisting solely of double white lines on a regular basis, versus using a physical yet permeable barrier (such as flexible guide posts) that a driver might not consider crossing to avoid a sudden collision.

[thenetwork]

What is going to be interesting is that for the next 2 years, CDOT will be building a 4th lane on I-25 between County Line and Lincoln.  It will be interesting if the Direct Lane will remain &/or enforced as such during and after the entire construction project.


...Meanwhile, much of C-470 just sighs and sulks with it's 2-lane stretches, wishing it could be widened to just 3 lanes.

[jakeroot]

Zmapper's comments are discussing the safety ramifications of drivers violating the barrier between express lane and general purpose lanes. Particularly, is it less safe for drivers to illegally cross the separation consisting solely of double white lines on a regular basis, versus using a physical yet permeable barrier (such as flexible guide posts) that a driver might not consider crossing to avoid a sudden collision.

thenetwork had another comment there that was talking about a detour in Utah or something, which is what I was replying to. Clearly, it isn't there anymore.

[Milepost61]

...Meanwhile, much of C-470 just sighs and sulks with it's 2-lane stretches, wishing it could be widened to just 3 lanes.

CDOT is going to do a design-build project to add managed toll lanes to it from Wadsworth to I-25. I think the schedule is currently to get a DB firm on board late in the year with construction starting early next year.

Unlike US 36 I don't think this will be P3, so CDOT will continue to operate and maintain the new toll lanes.

http://www.coloradodot.info/projects/c470ExpressLanes

[thenetwork]

...Meanwhile, much of C-470 just sighs and sulks with it's 2-lane stretches, wishing it could be widened to just 3 lanes.

CDOT is going to do a design-build project to add managed toll lanes to it from Wadsworth to I-25. I think the schedule is currently to get a DB firm on board late in the year with construction starting early next year.

Unlike US 36 I don't think this will be P3, so CDOT will continue to operate and maintain the new toll lanes.

http://www.coloradodot.info/projects/c470ExpressLanes

Good to know.  I have heard news on rebuilding and/or expansion for every freeway in town except for I-76, I-270 and C-470.  And it's those 3 freeways that suffer from "2-lane-itis" the most.  Okay, so the Boulder Turnpike/US-36 has 2-lane-itis as well, but they are have been trying to fix that problem for a while now.

[Milepost61]

CDOT ended the direct lane experiment this past Sunday, turning it back to a normal lane. CDOT noted "some" improvement in congestion and travel times, but "considerable" lane change violations.

http://www.coloradodot.info/news/2014-news-releases/08-2014/cdot-completes-i-25-southbound-pilot-program

[mrose]

A shame as 270 really needs a third lane badly.