Pity motorists caught in I-15 ‘collector-distributor’

When it’s 112 degrees or hotter in your car and traffic is stop-and-go on a freeway onramp, it’s natural to ask, “What’s gone wrong here?” Or worse.

I’ve had that feeling when traveling east on the 215 Beltway, taking the cloverleaf exit to get on northbound Interstate 15.

Only when you emerge from the end of that cloverleaf, you don’t actually get on I-15 — instead, you’re directed to a two-lane frontage road referred to in the engineering world as a “collector-distributor.”

It “collects” traffic from one or more merging entry points and “distributes” it to the main freeway — in this case, I-15.

Coming from the opposite direction (westbound Beltway), the merge onto I-15 isn’t so bad. There’s a braided system of overpasses and underpasses that puts the merging motorist right onto northbound I-15.

But pity the people caught in the collector-distributor. They include the previously noted eastbound Beltway traffic, the westbound Beltway traffic aiming to get to Russell Road, Tropicana Avenue and Frank Sinatra Drive and I-15 travelers exiting to Tropicana.

The distributor piece of the roadway moves cars to the right to exit on Russell, Tropicana and Frank Sinatra. (Actually, motorists get two shots at Frank Sinatra, the southern exit that takes motorists to Mandalay Bay, Luxor and Excalibur and the northern exit that empties at a signaled intersection and offers access to New York-New York, Monte Carlo and the resorts north of them.)

For those on the collector-distributor choosing to get on I-15, it’s an exit to the left — and that’s where the bottleneck occurs. Things get bogged down further because tourists unfamiliar with the access to I-15 are on the right, signaling to move into the merging I-15 lane.

In the merging lane onto I-15, the acceleration zone quickly disappears. Northbound I-15 traffic looking to exit at Flamingo Road encounters the merging traffic. Motorists getting on the freeway have no choice but to slow down and wait for an opening.

Warrior reader Jameel isn’t too subtle with his question:

“Who ultimately approved the final design for the travesty that is now the access ramp-frontage road from the 215 and Russell onto northbound I-15? It’s the absolute worst design I think possible.”

It’s not the worst design possible, Jameel. You probably didn’t live here when the Spaghetti Bowl was a four-loop cloverleaf design.

The answer to your question is the Nevada Transportation Department, and the good news is that engineers acknowledge the design is a problem and are working on a fix. But that won’t occur anytime soon because at this point, it’s just being studied.

Department spokeswoman Ranya Botros offered these details:

“We did recently execute a consultant agreement to begin the feasibility study on the Tropicana interchange at I-15,” she said. “A part of this study is addressing the lack of capacity on I-15 under the Tropicana bridge. The solution to the lack of capacity and backup on the northbound access road is replacement of the Tropicana bridge over I-15 and additional lanes on northbound I-15, so we can have a two-lane onramp from the northbound access road. This was identified in the I-15 South Design-Build Traffic analyses.

“The backups are at the project limits,” Botros said. “All projects, even a $250 million one, have limits. The backups and weaves now occur on the access roads, not the I-15 mainline freeway. Capacity on I-15 is up, overall delay in the corridor is down and accidents are way down from pre-I-15 South Design-Build levels.”

In other words, the answer is to redesign the Tropicana Avenue bridge over I-15 to allow more lanes of traffic, an expensive proposition.

Why wasn’t this done in the first place?

Engineers didn’t anticipate the capacity needs and consider what will be a really expensive fix.


Warrior reader Rose thinks it would be magical if some traffic disappeared from some streets in her neighborhood.

“I’m wondering if you could find out when a traffic light will be installed at Magic Way and Boulder Highway in Henderson. Boulder Highway in our area is getting a lot of traffic and across from us, more than 400 homes are being built.

“I went to a meeting several months ago and I asked that question. The answer was it will be installed and before I could ask when, the person answered, ‘Soon.’

“This intersection is dangerous and I am surprised there are not more accidents.”

There you have it, Rose. It will be done soon.

Actually, Keith Paul, a spokesman for the city of Henderson, offered a little more precision.

“The contract was awarded to Aggregate Industries on July 15 to install traffic signals at Magic Way and Boulder Highway,” Paul said.

“The contract allows for 90 days to procure the materials and then 110 days to finish construction. The project should be completed by February 2015.”


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