Downtown Santa Rosa bracing for Mendocino Avenue closure

Of all the criticisms of Santa Rosa's plan to reunify Old Courthouse Square - the outrage over the removal of mature redwood trees, the debate over park space versus parking spaces and the angst over the $10 million price tag - none has dogged the project more persistently than the concerns over traffic.

How, many ask, can the North Coast's largest city expect to sever a main traffic artery through the heart of an already congested downtown without triggering gridlock?

Well, we're about to find out.

On Friday, workers will permanently block off all four lanes of traffic running through the square, rerouting cars, buses and bicyclists around the site so workers can begin rejoining the two halves of the square split nearly 50 years ago by Mendocino Avenue.

It will be the most consequential and visible milestone in the controversial project to date, one that will directly affect thousands of drivers daily along one of the city's heaviest traveled corridors.

City officials say they've done everything they can to prepare downtown streets to handle the additional traffic loads, educate the public about alternate routes and remind people that all downtown businesses remain open during construction.

“I think the city is ready for this change,” said Julia Gonzalez, outreach coordinator for the city's Transportation and Public Works Department.

Originally, the city had wanted the contractor, Thompson Builders Corp., to finish reinstalling the two historic side streets, Hinton on the east and Exchange on the west, before blocking off traffic through the center.

Challenges dealing with underground utilities set the project back several weeks, forcing the city and contractor to move up the closure of Mendocino Avenue before the side streets were ready, said Jason Nutt, director of the Transportation and Public Works Department.

That shouldn't be a problem because those streets were never designed to handle through traffic, but rather were intended for business patrons and future park visitors, Nutt said.

They will be slow-speed, one-way streets with diagonal parking on each side, allowing cars to go north on Exchange and south on Hinton.

This clockwise pattern is counter-intuitive to some, who have criticized the design for “getting it backward,” Nutt said. They argue the traffic pattern should be counter-clockwise to let northbound traffic go up the east side of the square and southbound traffic travel down the west side.

But one of the goals of the project is to create a slower-paced, more welcoming space for those looking to spend time in the city's downtown “living room.” Moving the four lanes of traffic - which regularly exceeds 40 mph - from the heart of the city is seen as a key to create that more attractive downtown dynamic.

“Right now, it's a downtown that you drive through. We're building a space for people to drive to,” Gonzalez said.

Large signs have for weeks warned drivers of the changes, and additional detour signs will be added throughout the downtown in preparation for the Friday switch.

Lots of work has gone into making the changes go as smoothly as possible, but city officials expect challenges.

“It's going to be a hard day out there in the field for motorists and pedestrians,” Gonzalez said. “There's going to be a lot of activity.”

She urged drivers to be patient, give themselves extra time to get through downtown and consider other routes, including Highway 101.

Distance-wise, the main detour will not be long.

Southbound traffic will shift from Mendocino Avenue onto Healdsburg Avenue. Cars will also be able to cut over to B Street at several locations closer to the square.

Northbound drivers will have a bit trickier time. They'll turn west on First Street or Third Street, then head north on B. They'll then have to head east along Fifth, Seventh or Tenth streets to rejoin Mendocino Avenue.

Groundwork laid

Work to prepare the peripheral streets for the new traffic patterns kicked into high gear last week. Workers turned a one-way stretch of Fifth Street between Mendocino Avenue and B Street into a two-way roadway. They also tweaked the signals and restriped lanes of Third and B streets to handle the increase in northbound traffic.

This week, two left-turn lanes will be added to Santa Rosa Avenue to send northbound traffic west on Third Street.

Other changes were completed years ago, such as adding a second southbound lane to B Street and installing a traffic signal outside the Sears parking lot to help buses access the transit mall.

The prep work gives city officials confidence that the changes, while challenging for some drivers in the short term, will create an overall benefit to the downtown.

“I don't believe that the changes being made as part of the Courthouse Square project will result in major traffic disruption beyond the honeymoon period,” Nutt said.

Just how long that period will last and how much longer it could take to drive through downtown, however, Nutt couldn't say.

Given that northbound traffic will have several new turns and an additional signal to get through, his best guess is drivers will see delays of one to four minutes, depending on traffic levels and time of day.

A traffic study prepared in 2008 for the project concluded that with all the recommended changes, all downtown intersections would work at acceptable levels.

But the study also warned wait times at several intersections will increase. Of the 17 intersections studied, seven are expected to take longer to get through, while three will actually be faster, according to the study.

That study, however, assumed all the traffic - all 14,000 to 16,000 vehicles per day - would shift over onto B Street, which is not likely, Nutt said.

Once drivers get used to the changes, they'll adjust their routes accordingly, siphoning traffic off to other streets. Some may use E Street. Some may go through Railroad Square. Many others will simply decide to use Highway 101, something the city encourages for north-south through traffic.

“Traffic tends to function like water,” Nutt said. “It looks for the path of least resistance.”

No matter how fluid traffic may be, however, one place where it will still likely back up is the intersection of Third and B streets, already one of the busiest in the city. Third Street carries up to 27,000 cars per day west of B and 19,000 east of B. Those levels have held steady in recent years, which is why the city is comfortable using a 2008 study for a 2016 project, Nutt said.

Sending two northbound lanes onto a section of Third Street already congested during peak times is sure to exacerbate the problem. The traffic report projected motorists at that intersection would experience the longest delay - 68 seconds - of any downtown intersection.

“That one block is our challenge,” Nutt acknowledged.

Soon after those two lanes turn left to head west on Third, drivers trying to head north will have to merge into a single right-hand turn lane to go north on B. There's not a lot of room for this to occur, and if that merge backs up too far, it will block one of the two Third Street lanes carrying drivers west toward the highway, he noted.

To limit this, a right-turn arrow will have an extra-long cycle aimed at clearing northbound traffic out of that block as quickly as possible, Nutt said. Traffic engineers will monitor the intersection closely and adjust signal timing as necessary.

Also, to preserve the two westbound lanes, turning left onto B Street from Third will no longer be allowed.

While the traffic study predicts acceptable operations in the short-term, it also saw problems on the horizon. If the downtown gets built out as planned through 2030 - a big if - the study found that without upgrades, Third and B would get a failing grade of F, with average delays of 110 seconds.

The study suggests a number of changes, the main one being acquiring property from the Santa Rosa Plaza mall to install another lane on B Street. There are currently no such plans, but that is one of several options the city could explore to relieve future congestion if needed, Nutt said.

Down to business

Once Mendocino Avenue is blocked off, the contractor will rip up the cobblestone-lined street, largely completing the demolition phase of the work, Gonzalez said.

Construction of the new elements in the reunified square will begin soon thereafter, such as the installation of the central lawn and paved areas, wide sidewalks in front of businesses, and planting of dozens of new trees. The side streets are expected to be opened toward the end of the project, currently slated for Nov. 18.

That date couldn't come soon enough for many downtown businesses.

Some who are worried construction is already keeping customers away fret that traffic backups will cause even more to steer clear of downtown.

But Sonu Chandi, whose family owns three restaurants within a block of the square, said the city's recent conversion of Fifth Street from one-way to two was surprisingly uneventful.

Road crews made the switch in a matter of hours Thursday and drivers immediately began navigating the new route with ease, he said. It shows how people worry about change but then adapt, he said.

“Once people see the new signs and realize that's just the way it is, it's no big deal,” Chandi said.

Stu Patterson, co-owner of Flavor Bistro on the east side of the square, has worried in the past about the “traffic nightmare” the project will create. But the more he thought about it, he said, there will still be plenty of ways for people to get downtown, and, once complete, a reunified, open, accessible square should be great for business.

“I want to see downtown Santa Rosa become a destination,” Patterson said. “It could be a really cool scene.”