Caltrans has established an implementation date for use of the 2015 Construction Standards:
The 2015 Standards shall be used on all projects that Ready to List after June 30, 2016. All on-system projects advertised, awarded and administered by others with encroachment permits issued by the district after June 30, 2016, shall use the 2015 Standards. Districts are encouraged to use the 2015 Standards before June 30, 2016 in order to reduce bidder confusion and minimize contract administration difficulties. The 2010 Standards will not be supported after June 30, 2017.
Additional information can be found on the Caltrans Office Engineer website.