Archive for Monday, September 8, 2008

New signal order at busy intersection has drivers turned around

If you've noticed a change at one of the busiest intersections in town, you're not alone.

September 8, 2008


Engineer foresees intersection expansion

David Woosley, the city's traffic engineer, explains how the Iowa Street intersection at Clinton Parkway and 23rd Street could use some additional construction. Enlarge video

At the intersection of 23rd Street and Clinton Parkway, traffic wanting to turn west onto Clinton Parkway waits at a red light, at left, while northbound traffic proceeds through on a green light. The signals - for traffic turning from Iowa Street onto Clinton Parkway and 23rd Street - are set for "left-turn lag," so that turning vehicles from the north and south don&squot;t get crossed up.

At the intersection of 23rd Street and Clinton Parkway, traffic wanting to turn west onto Clinton Parkway waits at a red light, at left, while northbound traffic proceeds through on a green light. The signals - for traffic turning from Iowa Street onto Clinton Parkway and 23rd Street - are set for "left-turn lag," so that turning vehicles from the north and south don't get crossed up.

After turning left onto Clinton Parkway from Iowa Street five days a week on her way home from work, Sarah Warbritton thought she had it all figured out.

Then came the repaving machines, the new lane stripes and the second turn lane - all good moves for the inventory specialist at Verizon Wireless, freeing up more space for her to get out of the corner parking lot and on the way across town all the more quickly.

Then the green arrow wouldn't come on - or at least not until the traffic had turned left onto 23rd Street in front of her, the vehicles headed south had passed right beside her, and the others going north had sprinted out ahead of her.

"I've been a little bit confused," said Warbritton, who had grown used to turning at the beginning of the cycle for Iowa Street traffic, not at the end. "I thought maybe it was because it (the turn lane) was new, and the thing was broken or something."

No, it's much less problematic than that.

The turning movements for Warbritton and thousands of others who turn left onto Clinton Parkway from Iowa Street each day were adjusted to reflect a new reality for the intersection since its repaving earlier this summer.

Now that the intersection has double turn lanes on both sides of Iowa Street, there simply isn't room in the middle for all four lanes to go through at once, said David Woosley, the city's traffic engineer. That's why the signals now send turners from the north through the intersection at the beginning, while those coming from the south have to wait until the end.

"The outside left-turn lanes overlap," Woosley said. "Otherwise, those left turns would be turning into one another."

Woosley acknowledges that drivers may be confused when approaching the intersection from the south. Such a "lead-lag" signal pattern for turns is a first in Lawrence, he said, at least when it comes to avoiding potential crash conflicts.

The switch in signals won't be going away anytime soon, either. Woosley said that the only way that both double left turns would be allowed to go at the same time would be if the intersection were expanded, and that won't happen until someone finds some money to pay for widening Clinton Parkway and 23rd Street to make room for additional turn lanes on those streets.

"We've been wanting to do that since the 1990s," Woosley said.

But Warbritton isn't complaining. She already has the extra turn lane she needs.

"I like it," she said. "It makes it easier for me."


gccs14r 9 years, 9 months ago

"the traffic is larryville is the WORST .."Says the person who apparently has never driven anywhere else. I mean, c'mon. An afternoon in KC will show you that Lawrence doesn't have a traffic problem.

thomgreen 9 years, 9 months ago

It seems to me that they are systematically forcing all of the traffic off of the side streets onto the already congested main roads. If you don't want traffic on the neighborhood streets, why build streets in the first place? Every morning I sit at the light on 6th and Michigan upwards to 5 minutes waiting to make a left turn onto 6th street. All the while, there is little to no traffic on 6th street. Are street light systems not flexible enough to be timed at one point in the day and sensored at another?

Curtis Lange 9 years, 9 months ago

So, when are two turn arrow lights going to be installed at 23rd and Iowa for the individual lanes instead of just the one there now? It isn't very natural to have one light controlling two lanes of traffic, especially turn lanes.[sidenote] The debacle at 19th and Louisiana gets me too. Why the left turn lights were changed from yield on green to it's own arrow makes no sense. The other thing that drives me crazy is still the people that think that is one looooong left turn lane heading west on 19th. No people, those are two seperate left turn lanes. Use them as such.

MaryKatesPillStash 9 years, 9 months ago

To those of you calling for Woosley's job--get your facts straight.First, hawkperchedatriverfront: The accident at 23rd and Iowa between the semi driver and the motorcyclist had nothing to do with the new signal phasing, nor did it have anything to do with the alignment of the left turn lanes. The semi was turning left onto Iowa, and the motorcyclist was headed straight east through the intersection:, FYI Curtis Lange: It is somewhat (but not extremely) unusual to only have one left-turn signal head for a double left-turn lane. However, the Manual on Uniform Traffic Control Devices, the book that regulates the when, where, how, and how many of traffic signals and signs, only requires one signal head for that movement. Sure, a lot of places have double signal heads. But budget is a big factor in Lawrence. A signal head alone is upward of $10,000. In addition, the control cabinet (those boxes at every intersection--which, by the way, cost upward of $50,000!) may need to be upgraded to incorporate the extra 2 signal heads, which is more $$$$$$.Here's the MUTCD if you're interested. The signal head requirements are found in section 4D.15:, to all of you griping about expanding the number of lanes on various streets, and even sychronizing signals: I know it doesn't quite sink in, but this stuff is expensive to the point of being virtually impossible in Lawrence. Expanding lanes means land has to be acquired from landowners who may not necessarily be willing to give it up. $$. It means sidewalks have to be torn up and replaced. $$$. It also means utilities buried in the current right-of-way must be dug up and reburied in the newly acquired ROW. $$$$$ ++. Synchonizing signals is also expensive, and must frequently be reconfigured as emergency vehicles often re-set traffic signals as they pass through.If you aren't happy with the road, get a bike, and as so many of you often eloquently state, STAY OFF THE ROAD!

royalpain 9 years, 9 months ago

Glad to see someone quoted the MUTCD. The average citizen has no idea what goes into designing or modifying an intersection. Leave the details up to the engineers. Obey the law and pay attention. The intersections would not have been built if they weren't designed correctly.

ralphralph 9 years, 9 months ago

Finish the SLT and get a lot of traffic off 23rd?Nah!

situveux1 9 years, 9 months ago

If they don't want to build more lanes than at least look at some smart systems like they have in KC. They just started timing a whole stretch of lights on the Missouri side so that you didn't have to stop at every intersection. Why can't they do that with 23rd? Get them timed so a majority of traffic flows rather than has to stop at every intersection!

igby 9 years, 9 months ago

Hawk: Agreed, nowhere in America, is a light retarded like this one is, he needs to go and the intersection needs too be re-done. There's already been one biker killed while the lanes were being painted. This intersection is flawed with these extra lanes we did not need. Why have them if their flawed like this one. It's better too wait for another light change anyway. The federal highway safety board needs to investigate this and the city commission and planning department needs to correct the problem even if it cost another 2 million dollars. Then vote these dome CC's out of office in 2009!

Curtis Lange 9 years, 9 months ago

conservative, no that should not have factored in with that accident. Those two vehicles were in the east/west lanes of 23rd St. These signals are for the north/south lanes of Iowa.

sjschlag 9 years, 9 months ago

23rd and Iowa is easily the worst intersection in this city. Not a week goes by without an accident of some kind. The motorcycle, the roll-over last weekend, surely with the frequency of accidents the city would figure out someway to make the intersection actually work, right?Apparently not. I always dread making a left turn off of 23rd on to Iowa, especially when driving the bus, because I know I will be waiting in the left turn lane for 2, some times 3 light cycles. It makes me late every time. Something needs to be done about this light.

Thats_messed_up 9 years, 9 months ago

Woosley's got to be the worst traffic engineer in the U.S. How is it that every left turn signal in Lawrence is green only long enough to get the first 3 or 4 cars through? Lights turn red for cars that are not there all over town. More half-a$$ed Lawrence. Oh but we are getting another traffic stifling roundabout on O'Connell road--that's two within a quarter mile of each other! Plenty of money for roundabouts still!

Curtis Lange 9 years, 9 months ago

MaryKate, trust me, I know about the MUTCD. I've always joked that I should have looked into doing something with traffic engineering instead of weather/geography. Still may someday. However, most people expect there to be one signal per lane. Me personally, I don't have a problem with how that intersection is set up. Just pointing out some observations.

situveux1 9 years, 9 months ago

The light at 19th and Haskell has been on timers since the beginning of the summer. When I asked why it was on timers I got told a sensing loop had broken and it was on timers until it was fixed. Here we are months later and it's still not fixed. How long does it take to get something done in this city?Why is money not being spent to expand 23rd to six lanes? Why not add turning lanes at all intersections on 23rd? Why not expand 19th to four lanes? All ideas that need to happen but never will because we're too busy wasting money on other things.

conservative 9 years, 9 months ago

Hawk I also had noticed that the fatal accident at 23rd and Iowa happened on the same day as the new traffic signal pattern. Not sure if it played a part (and anticipating a light and going through red isn't a defense) but have been wondering.

coltrane 9 years, 9 months ago

what a great place for a super large ROUNDABOUT !Kansas would be famous for sure !

Fatty_McButterpants 9 years, 9 months ago

Seriously? People are that confused by an intersection? Just follow the signals! It ain't rocket science...

working_momma 9 years, 9 months ago

While I do agree that the newly remodeled intersection is not the most convienient, I am at least smart enough to aviod it if at all possible. We all have the choice to live, work and drive here in Lawrence, and yes, we are also afforded the right to complain, but c'mon the city is not going to change this next week because of a bunch of whiners on the internet. I think the more noble goal would be to encourage a lesson be learned and avoid it in the future.

1029 9 years, 9 months ago

'"The outside left-turn lanes overlap," Woosley said. "Otherwise, those left turns would be turning into one another."'Ok, this makes sense. Can you explain the disaster that 19th Street was turned into around LHS.? (a) The timing of the lights makes absolutely no sense and clogs the flow of traffic between Louisiana and Kentucky. (b) Eastbound cars trying to turn north on Ohio now back up traffic all the way back to the cars trying to turn east on to 19th from Louisiana. If there hasn't been one already, it's only a matter of time before this the elimination of the turn lane causes an accident (c) They may have fixed this one, but cars waiting to make a left turn southbound on Lousiania would line up at a red arrow--no more "yield on green"--even when there were no other cars anywhere near the intersection. (d) The way that the right lane ends on 19th Street heading east is a disaster waiting to happen--especially with LHS traffic and the teenage tendency to try to race cars out of the light. Unless people are familiar with the intersection, no rational person would ever anticipate the way the main lane abruptly shifts to the left and what seems like should be the main lane abruptly ends east of Kentucky. Look forward to drivers now trying to find ways to avoid 19th Street. It's no longer an easy east-west alternative to 23rd. Louisiania Street is no longer the convenient way to go to get to South Iowa Street (they should put a sign by the red arrow that says "we don't trust you"). Hope residents of University Place enjoy the increased traffic. I kind of got used to taking 17th Street anyway.

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