Question:  Some traffic signals in snow country with LED lamps are getting clogged with snow.  Are there any new products to address this problem? 

Answer:  The lower wattage of LED traffic signal heads compared to incandescent also means the lamps generate less heat.  This allows snow or ice to form on the head and sometimes block the display.  In at least one case in Wisconsin, it has become a legal issue.  See http://www.todaystmj4.com/news/local/79008352.html

McCain Traffic Supply has d...

Question:  I travel the same route to work on the same streets and at approximately at the same time 5 days a week. So here it is a holiday week and yes, traffic is lighter but then that gets me into work earlier. Why is it sometimes left-hand signals will be quick and other times they TAKE FOREVER. Is it lighter traffic not triggering the signal or is it time of day?

Answer:  The easy part of your question is the very last.  A traffic signal detector, with very few exceptions, is binary.  Y...

Question:  When Caltrans knows of a big traffic congestion problem, for example at 880 and Stevens Creek (the exit to Valley Fair and Santana Row), what organizations are involved to fix that kind of a big congestion problem? How long would it take, once approvals were passed, would it take to construct the solution?

Answer:  Great question for Mr. Roadshow of the SJ Mercury News.  Gary Richards just published some great news for you (posted 12/17/09):

“Bay Area transportation planners ha...

Question:  I’ve been told Caltrans recently issued new guidelines on accommodating bicycles at signalized intersections.  Where can I find the details?

Answer:  In August, 2009, Caltrans issued a Policy Directive about new requirements for bicycle detection at signalized intersections and new guidelines for traffic signal timing to accommodate bicycle travel speeds.  You can find the full document at http://www.dot.ca.gov/hq/traffops/signtech/signdel/policy/09-06.pdf.  The document describ...