Q I drove the Interstate 5 single lane area southbound near Buttonwillow last Friday that you recently warned about. Traffic was completely stopped for about five minutes but then resumed at 50 mph through the lane closure, which ended at Highway 119. It was a brief delay, hardly worth detouring around. If that's as bad as it gets, then I wouldn't recommend that motorists take Highway 101 to Southern California.

Gordon Hamachi

Mountain View

A Ah, but then you stayed on I-5 the rest of the way south and ...

Q Okay, you win. Next time Mr. Roadshow says to take 101 to L.A., I'll do it. In addition to the Buttonwillow single lane closure on I-5, the right two lanes were closed on the Grapevine. More lanes were closed in Santa Clarita Valley. After departing at 4:30 p.m., I didn't arrive at my destination until almost midnight.

Gordon Hamachi

A So what is normally a six-hour trip took 71/2 hours. Listen to Mr. Roadshow. Anything else?

Q I thought you might be amused by the story of my return trip from L.A. As promised, I took 101 instead of I-5. The 101 route is somewhat longer and the posted speed limit is lower for much of the route, so various Internet resources said it may take about 6 hours and 20 minutes, an extra 20 minutes more than the I-5 route. My hope was that by avoiding the I-5 lane closures I would have a faster return trip.

Unfortunately there were problems on this route too. Departing at 8:30 a.m. on Sunday, I encountered three lane closures even before I got to Santa Barbara. Between Santa Maria and Paso Robles, there was enough traffic to keep me below the 65-mph speed limit. North of Prunedale there was a lengthy traffic delay, evidently due to a collision. As a result, my return trip on 101 took 7.5 hours, almost exactly the same as for my Friday drive to LA on I-5.

Gordon Hamachi

A Let this be a warning to all I-5 and 101 travelers. Much of this work will last well into October.

Q I appreciated your comments earlier about using 101 to visit Southern California rather than I-5, but ...

Several weeks ago we went to L.A./Newport Beach on 101 on a Sunday and returned the following Saturday. We found that 101 is even worse or equally bad.

First, 101 from Santa Barbara to Ventura County narrows from three to two lanes into a huge traffic jam. On a Sunday going south around 4 p.m. we were stuck for over an hour. When we reached the L.A. County line near Thousand Oaks and headed south on 101/405, it was 70 mph all the way to Newport Beach. But our return to San Jose on the following Saturday late afternoon on 101 through Ventura and Santa Barbara was also very bad due to the narrowed highway. There were no accidents to explain the problems. I guess it's a double whammy.

Joel Zizmor

San Jose

A It can be. Traffic should be even heavier next week, as many colleges in Southern California begin classes and Bay Area residents make their trips south.

Q Is there a minimum speed at which cars must travel on the freeways? On separate occasions I've come upon cars traveling at 58 or 60 mph in the No. 2 lane on Interstate 580. Then I heard a man tell his wife that the minimum speed on a freeway is 45 mph, so I thought I'd ask you.

Sonia Quintana

Castro Valley

A There is no minimum speed limit on state freeways, although a few other states do have a 45 mph minimum. But drivers can be cited for not keeping up with the flow of traffic.

Q My husband and I witnessed a very scary scene recently. We followed a woman through our neighborhood in Concord who was cycling with a little trailer behind her bike, presumably with a child in it. She was pretty much in the middle of her lane. As she approached Treat Boulevard, the light was changing to yellow, but she sped up and entered the intersection on the red light. The street has eight lanes at that point, and we expected to witness a horrible tragedy. Fortunately, other drivers noticed the bicycle and didn't instantly accelerate when they got the green light. This is only a mile from where there was a tragic double fatality in April. What was that woman thinking?

Murnee Bowes

Concord

A Apparently she wasn't. Bicyclists could greatly improve their image by heeding red lights. Of course, many motorists could do the same.

Look for Gary at www.facebook.com/mr.roadshow or contact him at mrroadshow@mercurynews.com or 408-920-5335.