Several new roundabouts coming to SLO. Are they the best way to improve traffic flow?

SLO has plans for several new roundabouts

The city of San Luis Obispo, California, is planning six new roundabouts with at least one more under consideration on Highway 227. The city believes they can be an effective traffic flow measure.
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The city of San Luis Obispo, California, is planning six new roundabouts with at least one more under consideration on Highway 227. The city believes they can be an effective traffic flow measure.

A total of seven new roundabouts could be added to the San Luis Obispo area over the next few years — and at least some residents living just south of the city are none too pleased about a potential one on Highway 227.

Plans for roundabouts call for six new traffic circles within SLO’s limits to add to the existing four roundabouts citywide.

Additionally, on Highway 227 at the junction with Los Ranchos Road in county jurisdiction, a controversial roundabout is under consideration by the county Public Works Department. That new design would require final approval from Caltrans after further traffic engineering study.

The six new roundabouts in SLO will mostly be added with incoming new housing developments, city officials say.

But SLO also is planning a new $2 million traffic circle at an existing heavily trafficked intersection at California Boulevard and Taft Street near Cal Poly and the CHP office.

“If you design roundabouts correctly, they have really positive effects,” said Tim Bochum, the city’s deputy director of transportation. “But it takes community buy-in.”

In a 2017 preliminary study of the Highway 227 corridor, a San Luis Obispo Council of Governments (SLOCOG) report identified four new roundabouts as a preferred roadway traffic relief option within a few miles of SLO’s south end — Los Ranchos Road, Farmhouse Lane, Buckley Road and Crestmont Drive.

But Los Ranchos is the only option that’s funded and under consideration at this point.

On busy days, the corridor, which some commuters use as an alternative to Highway 101, accommodates more than 20,000 cars traveling between SLO and the South County.

A rendering shows a potential roundabout at Highway 227 and Los Ranchos Road south of San Luis Obispo. SLO County Public Works

At a March meeting on the planning that drew about 250 community members, many residents living near the Country Club and in the Rolling Hills community voiced strong objections to Highway 227 roundabouts.

“The proposal is not a solution. It’s a terrible idea,” said resident Joe Rouleau. “The city of San Luis Obispo, the county and Caltrans helped cause the problem by growing without concerns for traffic, and little long-range planning, exacerbated by Highway 101 congestion.. With roundabouts, the problem will only get worse.”

Rouleau said the neighborhood sentiment of opposition was nearly unanimous.

The county — working in conjunction with SLOCOG and Caltrans — will continue to explore a roundabout concept at Highway 227 and Los Ranchos Road that could potentially be a viable option to improve traffic flow.

Road widening and enhanced signals also are potential fixes.

“The detailed traffic engineering analysis will determine whether a roundabout, a wider road with improved signals, or no project at all is the best alternative,” said Cori Marsalek, the county’s project manager.

SLO promotes roundabout safety

In June, SLO released a series of user videos detailing how to drive, ride a bike or walk through a roundabout. Tips include yielding to oncoming traffic to the left and having inexperienced cyclists use the sidewalk versus the roadway, while more experienced cyclists might share the road with cars.

“Roundabouts are the city’s preferred form of intersection control,” the city wrote in a press release. “They help traffic flow more efficiently, with fewer delays and greenhouse gas emissions compared to a traffic signal or all-way stop.”

The city added roundabouts help reduce wait times for cyclists and pedestrians and decrease potential for severe accidents.

SLO cites fewer conflict points than conventional intersections, noting Federal Highway Administration statistics that show roundabouts reduce overall crashes by 37 percent and injury crashes by 51 percent.

“In a roundabout, you avoid the really dangerous right-angle collisions,” Bochum said.

The city’s existing roundabouts are on: Prado Road and Serra Meadows Road, Railroad Avenue and Osos Street, Madonna Road and Devaul Ranch Drive, and a new one at Tank Farm and Righetti.

Additionally, six additional roundabouts are being planned in the following locations:

California and Taft (currently proposed for construction in 2020 and estimated to cost $2 million)

Orcutt and Ranch House Road (part of the Orcutt Area development)

Tiburon and Ranch House Road (part of the Orcutt Area development)

Tiburon and Righetti Ranch Road (part of the Orcutt Area development)

Froom Ranch and Dalidio (part of the San Luis Ranch development)

Tank Farm and Orcutt (part of the Orcutt Area development)

The new roundabouts mostly are paid for up front by private developers, who absorb their fair share of costs with subsequent reimbursements for the rest, said Jennifer Rice, a city transportation engineer.

Transportation impact fees collected from new development citywide over time are used to reimburse developers for the portion of funding they’re owed.

For the California and Taft project, Cal Poly paid a portion of its fair share with the rest coming from the city’s General Fund, Rice said.

The intersection of California and Taft is one of the six potential roundabouts planned in the city of SLO. Scott Middlecamp

Highway 227 neighbors object

While the SLO city roundabouts are mostly in residential areas with relatively low traffic speeds, the new roundabout proposed at Highway 227 and Los Ranchos Road would require slowing vehicles down as they approach the traffic circle.

Curves in the roadway would be introduced to help reduce speeds, said Marsalek, of County Public Works.

“Roundabouts are designed to naturally slow vehicles down to 20 or 30 mph as they approach the roundabout,” Marsalek said.

The cost to build the roundabout at that location is about $5.5 million, which is fully funded through SLOCOG. But the project would need to be approved by Caltrans, according to Rich Murphy, a SLOCOG programming director.

Buckley Road and Highway 227 are one of the proposed intersections slated for roundabouts. Scott Middlecamp

More funding would be needed to build any additional roundabouts on the Highway 227 corridor beyond the potential Los Ranchos circle, Murphy said.

While the county will need to conduct further analysis about a Los Ranchos roundabout, a group of residents living near Highway 227 who spoke with The Tribune expressed a variety of concerns.

They contend that roundabouts would:

add to the congestion and make it more difficult to turn onto the highway from roads such as Crestmont, Los Ranchos and Biddle Ranch Road

lead to more accidents than widening the road and installing a new traffic signal plan

cause unsafe traffic flow that will stall with a mixture of farm vehicles, buses, cars and trucks, and bicycles

With a school in the area, Rouleau said a roundabout “will be particularly hazardous for younger bicycle riders.”

“If two vehicles, semis or pickups towing trailers both enter a roundabout at the same time, it will bring traffic nearly to a stop,” Rouleau said.

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Los Ranchos Road and Highway 227 is another intersection that could be a site of a roundabout. Scott Middlecamp

Residents believe widening a stretch of Highway 227 in both directions and synchronizing traffic lights is a better and safer option.

They also say more can be done to widen Highway 101, where an additional southbound freeway lane from SLO currently is being planned to help relieve commuter traffic to South County.

Marsalek said the detailed traffic engineering analysis will be shared with the public for additional feedback next year, adding that the community has helped shape the analysis.

“Not only is the county looking into what solution is best for the intersection of Los Ranchos Road but also what improvements could be made to Crestmont Drive, Biddle Ranch Road and Buckley Road to reduce traffic congestion and improve side streets,” Marsalek said.

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Nick Wilson covers the city of San Luis Obispo and has been a reporter at The Tribune in San Luis Obispo since 2004. He also writes regularly about K-12 education, Cal Poly, Morro Bay and Los Osos. He is a graduate of UC Santa Barbara and UC Berkeley and is originally from Ojai.