Showing Tag: "systems" (Show all posts)

Battery Backup Systems for Traffic Signals

Posted by Steve Fitzsimons on Tuesday, February 28, 2017, In : For Traffic Signal Designers 
Battery backup systems (BBS) are equivalent to a UPS that keeps traffic signals running for two or more hours after a power failure.   The photo shows a Type 332 controller cabinet (typical installation on a Caltrans highway) and the somewhat smaller cabinet on the right is the BBS.  BBS started seeing interest in California about 2001 when the state had an unusually high number of brownouts.   BBS started getting deployed in greater numbers in about 2004 after a CPUC study documented their b...
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Standard Procedures for BBS

Posted by Steve Fitzsimons on Monday, April 25, 2011, In : For Traffic Signal Designers 

Question:  What are the best procedures for installing and maintaining Battery Backup Systems? 

 

:Answer:   Republic ITS recommends installing BBS only at critical or important locations, and at least annual testing and replacement of batteries on a 3-5 year schedule.  A quick review of ITE and IMSA websites did not show any relevant publications.  Surveying a few SF Bay Area agencies revealed the following:

  •  Battery life seems to be about 5 years.  Costs to repair batteries is about $1...


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Traveler Information Systems

Posted by Steve Fitzsimons on Tuesday, September 22, 2009, In : For the General Public 

Question:  How do the radio stations and TV stations know when there are traffic jams? Are there sensors in the street itself? Do they all go to websites where all of the cameras we see on the signal lights are coordinated and the information goes to one place? Is there one centralized place where all of these people go to for their information? Do they have to call or go to all the different websites?  Is it true what you see on TV or in the movies how people can hack into one place and see ...


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Small Fiber Optic Splice Closure

Posted by Steve Fitzsimons on Thursday, June 25, 2009, In : For ITS Designers 

Question:  We have a project where some existing pull boxes and conduit are set in structural concrete and are not easy to relocate or deepen or change.

The pull boxes have a solid concrete bottom as well as walls.  They are No. 6 in plan dimension (18x30 lid) but their depth varies from only 5 to about 12 inches (different boxes are different depths).  Three conduits enter each box in the bottom (not through sides).  We need to run a 24 strand trunk loose tube single mode fiber cable through...


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About Us


Steve Fitzsimons If you would like to ask a question about driving rules, traffic signals or street lights, send your questions to: SFitzsimons@W-Trans.com or call 650-314-8313. Steve Fitzsimons is a professional Civil Engineer and Traffic Engineer in California. He is a principal at W-Trans. Find out more about W-Trans at www.w-trans.com **** If you need a traffic signal design or review, W-Trans is available for hire. If you are an electrical contractor, W-Trans is available for hire to prepare timing plans or traffic control plans.

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