After more than a decade of work, a deeply controversial effort to transform Palo Alto's Charleston-Arastradero corridor into a "complete street" full of bike lanes, crosswalk improvements and other traffic-calming measures is now entering its final stretch.

The Planning and Transportation Commission on Wednesday night gave its blessing to the last phase of a traffic project that continues to polarize Palo Altans. While bicycle advocates and school representatives laud the project for calming traffic, critics blame it for enraging drivers. PTA leaders see Charleston-Arastradero as a critical bicycle corridor for the children who attend the 11 schools nearby, but many residents in the surrounding neighborhood consider it a sclerotic artery and blame it for driving traffic into the adjacent neighborhoods.

The changes being proposed are the third phase of a project that began in 2003. The first phase, along Charleston Road between Fabian Way and El Camino Real, was completed in 2006 and the second phase, on Arastradero Road between El Camino and Gunn High School, followed suit in 2010.

The most dramatic and controversial component of both phases was the reduction of lanes from four to two at various segments of the corridor. The third phase will further cement these changes through hardscape improvements. It will also add a slew of new traffic-calming measures, including two crosswalks near Gunn High, one of them leading to a new multi-use path going toward Los Altos. There would also be new bike lanes crossing El Camino; a new right-turn lane near Terman Middle School; a new concrete median on the west side of Alma Street near Park Boulevard to prevent left turns to and from Park; and a landscaped median island near Hoover Elementary that prohibits left turns and U-turns.

Both supporters and opponents made their cases before the planning commission voted 6-0 to support the project. Cheryl Lilienstein, president of the citizens group Palo Altans for Sensible Zoning, said that she understands the importance of having "so-called 'complete streets,' these streets are not complete if cars can't pass." Recently, she said, it took her son 30 minutes to get from the Page Mill Road and Arastradero intersection to her house, 3 miles away.

Suzanne Keehn cited a recent morning when the traffic turning left from El Camino onto Arastradero was backed up for two blocks.

"By making less lanes and making more 'calm,' I think you will add to a lot of frustrations and stress for people," Keehn said. "You want kids to be safe, but you will not get people out of cars by making (driving) harder and harder."

Some critics blamed the recent traffic improvements for diverting traffic onto their blocks. Jim Jurkovich was among them.

"This plan, where we limited the lanes of traffic along Arastradero, has really caused traffic to shift into the neighborhoods and that doesn't achieve the goals," Jurkovich said. "The plan presented tonight doesn't really address the concern of the neighboring community about how we will handle the current traffic load as well as increased traffic load on the street."

But city staff and supporters of the project said it's wrong to blame the traffic problems on the changes on Charleston and Arastradero. Jim Lightfoot, the city's interim chief transportation officer, acknowledged the worsening traffic on this and other local corridors, a trend that he attributed to the growing economy and increased employment. This specific project, he said, will not make traffic any worse.

"The specific Charleston-Arastradero project will not change the capacity or the operation in the corridor," Lightfoot said. "We analyzed and looked at the level of service in the corridor and that doesn't change with the improvements being provided."

The project, he said, includes a number of things with benefits to "all modes" of transportation.

The city had studied the impacts of recent road changes in 2012, just before the council voted to make the Arastradero reconfiguration permanent. At the time, the city's study indicated that traffic volumes on Arastradero and adjacent streets "have shown a consistent increase in traffic compared to other streets in Palo Alto, consistent travel time between pre-project and project conditions, a reduction in high traffic speeds during off--peak hours, and a substantial reduction in pedestrian and bicycle related incidents."

The report also noted that bicycle traffic on and along the corridor has increased since the changes were implemented.

Andrew Volmer, who lives in the area, was one of many supporters who spoke at the meeting. Volmer, has two children who attend Fairmeadow Elementary School and called Charleston-Arastradero a "community street." He encouraged city officials to "move forward with a new plan for a permanent solution for this traffic."

"In whole, it will benefit all users of the street and make a better community," Volmer said.

Some supporters acknowledged that the new changes may force cars to go slower but argued that this is a price worth paying for safety. Peggy Kraft, one of more than 50 people who attended the hearing, said she sees the increased traffic as a natural byproduct of city growth. In praising the changes, she recalled her recent experience of bicycling on Arastradero.

"I was happy to go slowly and I was happy that the cars were going slowly; that people were biking next to me," Kraft said. "I feel like everyone is safer."

The commission spent more than two hours considering various issues raised by critics, including left-turn access into various properties along the street and potential worsening of the traffic conditions. In the end, all six commissioners went along with the staff recommendation to support the project, which will now go to the City Council for approval. Historically, the council has enthusiastically supported changes on the corridor. Last year, the council included $7.5 million for improvements on Charleston-Arastradero in its infrastructure-funding plan.

"I'm really excited about the idea that we can close the book on a 13-year-long effort," Commissioner Michael Alcheck said Wednesday. "In an ideal world, we make the process of improving our streets and our community as accessible as possible and as efficient as possible. I just hope that we can move forward with these conceptual plans and turn them into reality."

Commissioner Mark Michael concurred.

"The tradeoff for increased safety and traffic calming is worthwhile, which is why I support the motion (to recommend the concept)," Michael said. "I think it's the right thing to do."