The rest of the state calls it Highway 101, but in Oceanside it’s either Coast Highway or Hill Street. Whatever you call it, it’s going through an identity crisis.

Last month, the city repainted a half-mile section of the 101 known as “the dip,” removing two of the four travel lanes and adding buffered bike lanes – essentially implementing what’s known as a road diet, where lanes are reduced or reconfigured to make travel more efficient and safe.

It touched off a debate about Coast Highway’s rightful role in town.

To many the project was an obvious fix to a traffic flaw. Last fall, a 12-year-old boy was struck and killed in the dip while riding his bike to school.

Others said the change made things worse for the highways’ most important users: drivers.

But the project is the result of years of studies and planning from Oceanside, and was part of a study on a future road design that began in 2013. It’s being treated as a pilot project that will let the city study how road diets work, to see if they’re viable for the rest of Coast Highway.

The city might not have much discretion over making more changes like the one at the dip, however.

For one, the city in 2009 adopted a plan called the “Coast Highway Vision,” which broadly calls for streets that are safe and enjoyable for drivers, transit riders, cyclists and pedestrians.

Plus, new rules under the California Environmental Quality Act that will take effect next year will make it increasingly difficult for cities to redesign roads in urban areas without implementing pedestrian and bicycle amenities.

Together, those two factors bind the city to a broader scope than simply looking at how long people have to wait at traffic lights.

Then there’s money – the San Diego Association of Governments provides grants to cities that undertake smart-growth projects. Oceanside can compete for those grants to implement the rest of the Coast Highway Vision, but it wouldn’t be available for simple repaving that maintains it as a four-lane road.

It’s looking like the end of the road for the car-only highway.

“If you think of Coast Highway as solely moving cars, then it will be only for moving cars, and it won’t be very successful as we’ve seen,” said Neal Payton, the principal at planning firm Torti Gallas, which wrote the Coast Highway Vision Plan. “Maybe that idea is past its day.”

The Vision

The broad goal of Oceanside’s plan for the 101 is to promote neighborhoods where people can live, work and go enjoy the town.

It’s not a specific development plan, but it does make it easier for developers to build the things that the plan prioritizes: more housing, restaurants, shops, grocery stores and other neighborhood needs.

But it also emphasizes building so-called complete streets, where you can hop in your car, ride your bike down to the grocery store, walk or take light-rail. The choice is yours, but you have real options.

To Payton it’s worth emphasizing that the goal itself came from the community.

“This was very much a public process, and sometimes it’s not stressed enough,” Payton said. “Let (the pilot study) evolve into it a little bit to see if it’s got any mojo.”

The plan lays out the broad goals for the future of the area. Now the city is implementing it with the pilot study’s changes to Coast Highway.

Some have called for the city to enable bicycle travel by providing a separate path off the road. But that would undercut the plan’s goals for creating a lively street.

“Complete streets are part and parcel of creating a neighborhood that’s economically more viable and more healthy for its citizens,” Payton said. “Cities that are able to take control of their streets – treat cars, bicycles and pedestrians equally – are going to win economically and environmentally.”

The Science of the Study

The city is measuring the results of its road diet not only on Coast Highway, but also on Pacific Street, the only street that can be used to bypass the dip.

David DiPierro, a traffic engineer with the city, said it will track three metrics: volume, speed and journey.

Volume and speed are traditional measures of traffic impact, which effectively look at congestion: how many cars are on the road, and how quickly are they moving through an area.

The city will run its volume and speed observations through an algorithm to determine how much the change contributed to congestion. It may ultimately find the road diet has a negative effect, Oceanside transportation planner John Amberson said.

The third metric, “journey,” tracks whether a particular vehicle chooses an alternate route to get around an area. It tracks a car using an anonymous identifier tied to the car’s Bluetooth system.

That will help determine whether cars are taking a longer but potentially quicker route around the road.

But pending changes to CEQA, the state’s premier environmental law, will further complicate how the city evaluates its pilot study. The changes are expected to take effect just as the city completes an environmental report on the project.

CEQA in 2017 will adopt a new metric for looking at how a project affects drivers. A draft of the proposal explains that cities will instead be asked to measure the distance cars travel due to a project, rather than looking at how much congestion results from a project.

If the rules are in effect first, the city will have to revise its traffic models, and redo its study to reflect the different measurement, Amberson said.

The state’s shift to measuring vehicle miles traveled hasn’t been finalized, but the draft proposal makes a few assumptions about how road diets would affect traffic.

One is that removing a lane of traffic isn’t going to increase the number of vehicles on the road.

Opponents of the road diet contend that reducing lanes may increase the amount of time cars are sitting in traffic. Even if that’s true, under new CEQA rules, that delay won’t be considered a big deal.

With a road diet, the city is putting itself on solid ground to deal with the state’s changes, Amberson said.

Under the new rules, it’s considered a good thing if people drive less due to the project. Under the old rules, the question was merely whether the project created any congestion.

“The idea of removing general purpose lanes decreases VMT, and is more beneficial (under the new rules),” Amberson said.

Likewise, the new rules assume projects that encourage people to drive more – such as road widenings that ease congestion to the point that more people choose to drive – have a significant effect on the environment.

In that way, the CEQA changes will help the city achieve its long-term vision by making it easier to implement a road diet and add bike lanes.

When the pilot study was approved in January, DiPierro , the city’s traffic engineer, said he would report back to the Council with the results after summer.

“No sunset was given on the project other than we were going to let the data provide guidance on if the project was working as intended,” DiPierro said. “Based on our analysis and modeling all indications are that it should work fine with minor congestion for northbound Coast Highway at Oceanside Boulevard during the (afternoon) peak-hour period.”

The City Council will decide at a special workshop April 13 whether to begin preparing an environmental impact report for the whole transportation corridor, or let the pilot study run its course for another year or so.

Council members, even the biggest supporters of the road diet, appear ready to wait to see if it’s got mojo.