Ever since Dwight Eisenhower moved into the White House six decades ago and gave a green light to the interstate highway system, the car has been king.

But today there is a new focus, one drawing howls of protest from some motorists but cheers of relief from pedestrians and bicyclists. Across the Bay Area and California, cities are removing or narrowing lanes and redesigning hundreds of streets to add bike lanes, speed up transit and improve pedestrian safety.

The car remains king, but the crown is slipping.

“There is a strong national and international movement to provide transportation for people and not just cars,” said Hans Larsen, director of San Jose’s Department of Transportation. “For decades, planning has focused on the efficient movement of cars. The result has been communities that are dependent on cars and are not conducive to walking and biking and transit.”

On Thursday, San Jose will convert sections of Fourth and St. James streets north of downtown from speedy, one-way routes into two-way roads to slow drivers down and make it easier for residents to cross intersections in their neighborhoods. Next month Santa Clara will begin the next phase of removing one lane on busy Pruneridge Avenue to install lanes for bicyclists.

Lanes may be removed on El Camino Real from the South Bay to South San Francisco to speed up buses, and Capitol Expressway may lose two lanes for light rail. San Francisco has slowed traffic lights on Valencia Street to match the speed of bicyclists, not cars.

And a slew of streets all over the Bay Area are getting similar makeovers: Arastradero Road in Palo Alto, San Mateo Drive in San Mateo, Veterans Boulevard in Redwood City, Grand Avenue in Oakland, Foothill Drive in Pleasanton and Mission Boulevard in Hayward.

Some changes began years ago, but the push toward “road diets,” as transportation planners call them, took off in 2008, when the state endorsed the concept of “complete streets” for urban neighborhoods in which the entire streetscape, from sidewalk to sidewalk, is geared for safe access and use by nondrivers.

It’s not all smooth sailing, however.

“You can’t make the streets too narrow; otherwise there would not be room for parking, which is in very short supply in our city,” said Don Frascinella, the transportation manager in Hayward. “One of the dangers is that you have to be very careful not to make the lanes on trucks and bus routes too narrow or passing vehicles might conflict.”

Last month when Santa Clara reduced Pruneridge from a four-lane road to one lane each way with a shared center-turn lane, some motorists howled.

The change is “completely nuts,” says commuter Santo Rao. “Now a slow-moving car can block up the entire road. While China is busy building future infrastructure to dominate the world, here we have harebrained folks doing the opposite, taking us back to one-lane roads.”

But to Lane Melcic, who has lived 40 years on Pruneridge, the new look is welcome.

“For decades residents have petitioned the city to do something about the unnecessary traffic,” he said, pleased that some fed-up drivers now are apparently using Wolfe Road to reach nearby Interstate 280 “instead of plowing through our neighborhood. Thankfully, it appears that someone has finally listened.”

San Jose transportation chief Larsen sees reducing vehicle lanes as a key to luring solo drivers out of their cars. Today, 80 percent of travel in the city is in single-occupant vehicles. The goal by 2040 is to reduce this to 40 percent and to increase bicycling and walking by 30 percent, transit use 20 percent and carpooling 10 percent.

Much of this shift is expected to result from future land development that has jobs, housing and retail services in closer proximity and located along transit station areas where people feel safer walking or bicycling.

The Federal Highway Administration looked at five cities — including Mountain View, Oakland and Sunnyvale — where four-lane roads had been reduced to three and found that crashes were down 6 percent. Other federal studies showed a similar decline in crashes involving pedestrians when they were crossing a street with just two through lanes compared to those with four.

“Complete streets is to me about choices,” said Chadrick Smalley, a development project manager with Richmond who last month gave a presentation on the program at the Metropolitan Transportation Commission in Oakland. “By designing and building complete streets, people are able to choose to walk, drive, bicycle or take transit. Streets that are designed solely for automobile travel often do not feasibly permit that choice to be made and, instead, force people to drive.”

What do you think of the “complete streets” plan, and has it affected you? Contact Gary Richards at mrroadshow@mercurynews.com or at 408-920-5335.