CEN ISO/TS 17426:2016

Delivering contextual speeds to road users can improve road safety, support traffic management and reduce greenhouse gas emissions.
In a co-operative ITS environment, contextual speeds are context-dependent (e.g. weather conditions), as well as time-specific and road section-specific authorized speeds. Subject to local regulations, they may be regulatory speed limits and/or recommended advisory ones.
This document will define and characterize "contextual speeds" in detail, with use cases. It will also specify the general service requirements for the support of this feature and provide recommendations for the definition of application profiles.