Q Can you answer a question about the new "Walk your bike" signs around downtown San Jose? As a regular walking user of the sidewalks downtown, I was excited to see these signs go up, after a few close calls with bikes over the years.

One week, as I was waiting to cross San Fernando at Second, I overheard the middle of a conversation between two young women on bikes complaining about people walking on sidewalks who stutter-step when a bike approaches. The other agreed, commenting, "I wouldn't hit you if you'd just go straight."

The light changed, and one said to me as she passed on her bike, in the crosswalk, "Go straight." I held my tongue but wanted to say, "Walk your bike, and you wouldn't hit anyone." There is no city code number on the signs that have been posted. Is riding on the sidewalk a ticketable offense?

Katie Gillespie

San Jose

A No -- at least not yet. Those signs are part of a new pilot project downtown aimed at reducing sidewalk bicycling to reserve sidewalks for pedestrians. This summer San Jose will begin an outreach effort to encourage bicyclists to stay off sidewalks and use the 11 miles of bike lanes that now exist.

Q Will San Jose fix northbound Camden Avenue at Coleman Road? Camden is three lanes wide, then merges into two lanes after the Coleman intersection. I often see cars speeding down the hill on Camden while motorists are backed up in the third lane from Coleman (trying to get across to Hicks Road so they can get to Venture Christian Church). Will the city ever narrow Camden into two lanes ahead of Coleman?

Akeem Mostamandy

San Jose

A Yep. In the city's 2009 general plan, Camden was downgraded from a six-lane to a four-lane street from Almaden Expressway to Blossom Hill Road. Work will happen next summer during a paving project when the third lane is taken out and replaced with bicycle lanes.

Q What are the huge turbine-like fans in the new bore of the Caldecott Tunnel for and, if they serve any purpose, shouldn't we have them in the other bores as well?

Henry Hitz

Oakland

A We do have them in the older bores, you just can't see them. There are 19 jet fans along the length of the Caldecott's new fourth bore. The fans are part of the tunnel's state-of-the-art fire and life safety system, and are triggered by air quality thresholds, as measured by carbon monoxide/nitrous oxide sensors in the tunnel. These jet fans are visible to drivers and designed to direct smoke away from motorists in case of a fire.

The three older bores have different ventilation systems that are housed in compartments above the tunnel and cannot been seen by motorists. They are also designed to maintain air quality in the tunnels and to blow smoke away from drivers in the event of a fire.

Q I drive to Davis about once a week, and I have noticed that the stretch of Interstate 680 south from I-80 to the Benicia Bridge is quickly disintegrating. There is one section that has been resurfaced, but the rest of it has lots of cracks, potholes and some attempts at patching. Makes for a very tough and unpredictable ride. Any plans for resurfacing?

Cathy Aaron

Walnut Creek

A Your drive should get smoother, as a 14-mile paving project is scheduled to start next spring.

Q I was wondering about the closure of the Concord DMV office, which you referenced recently. Having recently stood in an extraordinarily long line at the Walnut Creek DMV office (and unable to get a online appointment until mid-June) due to this closure, why hasn't the DMV reassigned the Concord employees to Walnut Creek so that they could have extended hours on weekdays and open on weekends? What has happened to all the Concord DMV employees?

Deb T.

Concord

A The 30-person staff at Concord has been reassigned to offices in Walnut Creek, Pittsburg, Vallejo and Oakland while the office at Concord is being renovated. It will reopen Sept. 29. There are no plans to keep other offices open later or on weekends for budget reasons. I'd keep on trying the DMV online services, as almost all transactions that can be done in a field office can be done online.

Q Is Osgood Road in Fremont getting two lanes each way between Grimmer and Mission Boulevard?

Hari Kotcherlakota

Fremont

A Yep. Osgood will be widened to four lanes between Grimmer and Mission and later from Reliance to Mission. This should be done by late 2015 or before the BART Warm Springs station opens in Fremont.

Q I often use the Capitol and Tully connections with Freeway 101. Why have some of the cloverleaf exits from 101 to these streets been removed? Traffic backups in all directions at these connections are horrendous. Cloverleafs at these intersections would alleviate these backups by eliminating the need for some traffic lights, thereby enhancing the flow of traffic.

Harvey Wolfe

San Jose

A A bunch of engineers say you are wrong. Caltrans devised the new offramps and, although cloverleaf ramps allow for cars to move freely without stopping, that happens only if few cars are on the road. When traffic increases, the short weaving space between the loop ramps causes a terrible merging mess. In addition, the cloverleaf requires more room and costs a lot more. A partial cloverleaf design partially eliminates this weave and -- brace yourself -- actually allows for more cars to move through an interchange faster because some left turns can be eliminated.

Look for Gary Richards at Facebook.com/mr.roadshow, follow him at Twitter.com/mrroadshow or contact him at mrroadshow@mercurynews.com or 408-920-5335.