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Archive for the ‘Engineering/Facilities’ Category

Ask the traffic engineer: How are speed limits set?

January 30th, 2010 Bob Shanteau 2 comments

Most people think that motorists base their speeds on the speed limit. But while that may be true on freeways and other high speed highways, it’s not true on lower speed roads and streets. On lower speed roads and streets, motorists base their speeds not on the speed limit but on how the road feels.

If you’re typical, that doesn’t feel right to you. You may be thinking to yourself, doesn’t everyone pay attention to the speed limit like I do? Read more…

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Signal Timing Issues

November 29th, 2009 Brian DeSousa 1 comment

AB1581, which became law in 2008, requires all new or replaced traffic signals to respond to the presence of bicyclists. In addition, a requirement to develop signal timing guidance was also a part of AB1581. Both are incorporated in Policy Directive 09-06 from Caltrans.

The video clip below is of a cyclist making a left turn from a residential collector onto a six lane arterial. Although it’s a bit difficult to see in the video due to the wide angle lens, the cyclist’s position when the light turns green for traffic on the arterial is in the middle of the number two lane.  The cyclist reaches the bike lane on the other side at about 12 seconds after receiving the green.

Problems with Bike Lanes Striped Solid to the Intersection

November 8th, 2009 Dan Gutierrez 1 comment

Some of our friends in other states, as well as some local advocates have asked me about why bike lanes shouldn’t be striped solid at intersections. Here’s a picture of just such a facility in Florida, care of our friends at CommuteOrlando.com:

http://commuteorlando.com/wordpress/wp-content/uploads/2008/11/onramp1.jpg

Bike Lane Striped Solid at Intersection in Florida

  Bike Lane Striped Solid at Intersection in Florida

 

Here’s a slide that gives a visual representation of the problems created by this bike lane treatment (and even a wide lane under Far To Right law guidance): http://www.cyclistview.com/uploadedphotos/Incompatible-Destination-Lanes-Draft.jpg

Incompatible-Destination-Lanes-Draft-600x450 Problems with Incompatible Destination Lanes

 

And here’s a detailed explanation in terms of Engineering and Planning and the Legal/Operational issues that result: Read more…

Bike Lanes and Motorist Right Turns

November 2nd, 2009 Brian DeSousa 4 comments

Here’s an interesting article discussing how motorists should legally and safely make right turns in the presence of a bike lane (and no right turn only lane):  http://www.mercurynews.com/columns/ci_13669464 

California law requires motorists to merge into a bike lane before turning right.  This is consistent with destination positioning principles (right turning traffic turns from the rightmost part of the roadway) and thereby minimizes the chance of a “right hook” crash, where a right turning motorist turns across the path of a cyclist proceeding straight. 

A few years ago, Oregon was dealing with conflicting laws – one that required motorists to make right turns from the edge of the roadway, and yet another required them to stay out of bike lanes.  The police proposed a California-style law which would require motorists to merge into the bike lane before turning.  That did not gain traction, and so the net result in Oregon is that motorists are required to turn across bike lanes when turning right.  http://bikeportland.org/2006/11/29/police-propose-bike-lane-law-change/

Oregon has been moving in the direction of installing ”bike boxes” to address the right hook problem.  Here is an animation that shows they don’t work as intended in all situations: http://www.commuteorlando.com/ontheroad/animations/bikebox/

As the Mercury News article illustrates, there is often confusion among motorists and cyclists about the California law regarding motorist right turns and bike lanes.  In my (Brian’s) view, part of the confusion is that motorists are being asked to occupy two lanes at once (the bike lane and part of the travel lane) – which runs counter to the concept of only occupying one lane at a time. But what other solution is there when bike lanes are striped to the right of lanes where motorists may turn right? Since there seems to be little desire to drop the bike lane stripe before intersections, the California law appears to be the best way to address the potential conflicts.

City of LA Draft Bicycle Master Plan – Engineering Policy Problems

October 7th, 2009 Dan Gutierrez No comments

The current draft of the City of Los Angeles Bicycle Master Plan (BMP) gives up on bicyclist use of the vast majority of the roads in the city and focuses on bikeways. In effect, this plan allows LA Dept. of Transportation (LADOT) to simply ignore the overwhelming majority of roadways as facilities that bicyclists will use and relieves them of any obligation to make the surface standards, intersection designs, and signal detection support bicycling on this majority of roadways. What follows is a re-write of the top level policies with existing policies augmented and a small number of important new goals and policies added. My changes are identified by [square brackets]. Read more…

Proposed Bikeway in Long Beach – Letter to CBAC

September 30th, 2009 Bob Shanteau No comments

September 29, 2009

Ken McGuire, Secretary
California Bicycle Advisory Committee – MS1
P.O. Box 942874, Sacramento, CA-94274-0001

Subject: Proposal by City of Long Beach to Experiment with Separated/Protected Bikeway on the Left Side of Two One-Way Streets

by email to (email address deleted)

Dear Mr. McGuire:

The California Association of Bicycling Organizations (CABO) has reviewed the documents prepared by the City of Long Beach in support of a “protected bikeway” and notes that it fails to comply with the guidance and standards in the California Streets and Highways Code and Vehicle Code and in the Caltrans “Highway Design Manual”. In light of this noncompliance and the resulting potential problems of traffic safety, traffic operations, and the failure by the City to address the status of bicyclists as legitimate highway users, CABO hereby requests that CBAC adopt a finding that the Long Beach proposal fails to comply with these references and to forward this finding to the City of Long Beach. The reasons for this request are detailed below. Read more…

Proposed Bikeway in Long Beach – Letter to CTCDC

September 21st, 2009 Bob Shanteau No comments

September 21, 2009

Devinder Singh, Secretary
California Traffic Control Devices Committee – MS36
P.O. Box 942874, Sacramento, CA-94274-0001

Subject: Item 09-21 on 9/24/09 CTCDC agenda
Request by the City of Long Beach for Permission to Experiment with Separated/Protected Bikeway on the Left Side of Two-Way Streets (Rte 9-112E)

by email to (address deleted)

Dear Mr. Singh:

The California Association of Bicycling Organizations (CABO) has reviewed the subject Request to Experiment (RTE) and notes that it fails to acknowledge previous trials in California of separated bikeways, particularly in the City of Davis and the City of Palo Alto, both of which were abandoned in favor of the standard bikeways now defined in the California Streets and Highways Code, the Caltrans Highway Design Manual, and the California Manual on Uniform Traffic Control Devices. In light of this previous negative experience with separated bikeways and the potential problems of traffic safety, traffic operations, and the status of bicyclists as legitimate highway users, CABO hereby requests that CTCDC reject the subject RTE or, if the CTCDC feels that the RTE may still have merit, refer it to the California Bicycle Advisory Committee for a recommendation on action by the CTCDC. The reasons for this request are detailed below. Read more…

Bicycling Planning – Don’t Leave Out Shared Roadways!

September 14th, 2009 Bob Shanteau No comments

I mentioned South San Francisco’’s efforts to develop a comprehensive bicycle plan to Dan Gutierrez earlier today and we agreed that the plan should not only identify bicycle facilities, but also improvements on shared roadways such as:

Read more…

Traffic Engineering Expertise on-board with CABO

February 6th, 2009 Jim Baross 1 comment

I am pleased to announce that the California Association of Bicycling Organizations will benefit from the Traffic Engineering expertise, substantial history and involvement with bicycling advocacy of Robert (Bob) Shanteau. Read more…

Gore Separated Bike Lanes

August 23rd, 2008 Brian DeSousa No comments

A while back we gave a presentation to the California Bicycle Advisory Committee showing our concerns with gore separated bike lanes. An example of a gore separated bike lane is the photo of Pacific Coast Highway in Dana Point posted below.

The gist of the presentation was this:

  • The California MUTCD prohibits raised barriers or raised pavement markers between travel lanes and bike lanes. This is to avoid trapping cyclists when they need to leave the bike lane to make left turns, to pass another cyclist, to avoid debris, or to avoid conflicts with turning traffic.
  • It is illegal to cross a gore striped area two feet or wider. Therefore, the gore area has the same effect as a physical barrier between the travel lanes and bike lanes.
  • It is CABO’s position that gore separated bike lanes violate the intent of the provision prohibiting barriers between travel lanes and bike lanes. However, for clarity, CABO requested that the appropriate wording be added to specifically prohibit gore separated bike lanes.
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