Mount Diablo State Park Citations (2010 to 2018)

(Public Records Act Request)

No citations were issued to motorists for crossing the solid double centerline, passing on a blind curve or violating the 3ft rule (2016, 2017 or 2018)

Cyclists were significantly more likely to receive a citation than motorists or hikers for: Entering Park Early, Wearing Headphones, Basic Speed, Stop Signs (2010 - 2018) (Especially during the years 2012 to 2016)

"The last Radar Speed survey for Mount Diablo expired on April 30, 2008." "A valid Radar Speed Survey is generally required for Citations based solely on a radar or laser gun." 

Total Number of Citations for Cyclists, Motorists and Park Visitors

  • 2010 - 30 Citations
  • 2011 -  37 Citations
  • 2012 - 49 Citations
  • 2013 - 58 Citations
  • 2014 - 62 Citations
  • 2015 - 39 Citations
  • 2016 - 14 Citations
  • 2017 - 6 Citations
  • 2018 -  5 Citations
  • CVC 21202 - “substandard width lane is a lane that is too narrow for a bicycle and a vehicle to travel safely side by side within the lane,”
  • CVC 21760 - “3ft Rule
  • CVC 21460 - “crossing double parallel solid yellow lines

* Warnings Issued in Mount Diablo State Park

When will Park Rangers patrol the roads, especially South Gate Road on Saturday mornings and issue warnings to motorists for crossing solid double centerline, passing on blind curves or violating the 3ft rule ?

Lisa Mangat, Director, California State Parks            Nov 20, 2018

Dear Ms. Mangat,

Mount Diablo Cyclists remains concerned regarding the high number of near-miss and actual collisions involving cyclists.  As you are aware, on a typical weekend day, up to 500 drivers share the roads of Mount Diablo with approximately 700 cyclists. According to some estimates, over 150,000 cyclists rode and over 200,000 vehicles drove up and down Mount Diablo last year.

According to Park Leadership and supported by the responses in our Motorist Surveys, “most motorists entering the Park have never been to Mount Diablo before and are unaware that they will share the narrow, winding roads with hundreds of cyclists.” Recently, 128 cyclists completed a survey and reported a total of 336 unsafe passes on blind curves while riding up the mountain.  Given that only a portion of the total cyclists riding in the park on that Saturday participated in the survey, the total estimate of the number of unsafe passes would be over 1,000. Considering the number of cars, bikes and pedestrians on the park roads that day, it is remarkable that there were no serious collisions.

Our research shows that numerous near-miss bike vs vehicle collisions occur on a regular basis.  In addition, according to State Park documents, many collisions and injuries involving Park visitors have occurred in the 2 ½ mile road segment from the South Gate Entrance to the Kiosk.

At this time, we are requesting the following from California State Parks:

  1. Expedite the installation of Bike Turnouts on the roads of Mount Diablo.
  2. Contact the registered owners listed below and notify them that they were filmed driving unlawfully (crossing solid yellow lines, passing cyclists on blind curves and violating the “3-Foot Rule”) at Potential Bike Turnout Location #12, South Gate Road, Mount Diablo State Park.
  3. Blue Tesla (Lic# 8FZU958) b. Black Mitsubsi (Lic# 4NSY659)
  4. Blue SUV (Lic# 8CYN334) d. Light Blue Preis (Lic # 7KXI778)
  5. White SUV (Lic# Unknown) f. Grey/Silver Audi (Lic # 8CNS276)
  6. Grey VW (Lic # 7HEG159) h. Silver Mercedes (Lic# 7BKU855)
  7. Grey Van (Lic# 8F33792) j White Pries (Lic# 7YKC555)
  8. Silver Chev (Lic# Unknown) l. Ford F150 Truck (Lic# 5092002)
  9. Red Tesla (Lic# TSL8888) n. Silver/Grey Jeep SUV (Lic# 6ZHV614)
  10. Conduct Targeted Enforcement from the South Gate Entrance to the Kiosk regarding: crossing Solid Double Yellow Lines, passing cyclists on Blind Curves and violating the “3-Foot Rule.”
  11. Maintain a list of all “Warnings” and “Citations” given to motorists who cross Solid Double Yellow Lines, pass cyclists on Blind Curves and violate the “3-Foot Rule.”
  12. Reinstate the Electronic Sign reading: “DO NOT PASS BIKES ON BLIND CURVES” on South Gate Road.

In our opinion, it is not a question of if, but when the next Bike vs Vehicle Collision will occur, resulting in a serious injury or possibly a fatality. We believe that such a tragedy can be prevented.


Leadership Team, Mount Diablo Cyclists

Cc:  State Senator Steven Glazer, District 7

Marivel Barajas, Deputy Director, Legislative Affairs, California State Parks

Gloria Sandoval, Deputy Director, Public Affairs, California State Parks

Tara Lynch, Chief Counsel, California State Parks

Maria Mower, Bay Area Park District Superintendent

Ryen Goering, Contra-Solano Sector Superintendent

Dan Borenstein, Editor Contra Costa Times