The Los Angeles County Board of Supervisors voted Tuesday to make a series of changes in traffic regulations that affect some areas in the Santa Clarita Valley.

For the Stevenson Ranch community, an unincorporated part of the county, supervisors voted to adopt a traffic regulation establishing a 35 mph speed limit on Westridge Parkway between its westerly terminus of Stonegate Drive and Valencia Boulevard.

“For the first time, this portion of Westridge Parkway will have a set speed limit,” said Steven Frasher, public information officer for the county’s Public Works Department. “There were no codified speed regulations there; it was kind of like highway speed there.”

This area of the community is mainly residential and has nearby schools and recreation areas.

In Castaic, also an unincorporated portion of the county, eastbound traffic on Black Oak Lane at its intersection with The Old Road will receive a stop sign, according to a county board letter on the matter.

Eastbound traffic on Victoria Road and Pinto Place at The Old Road in Castaic already have stop signs but will be codified to “formalize what’s already there,” said Frasher.

The neighborhoods around these streets are also residential.

Selection of these traffic regulations stems from a traffic study conducted by the county as a result of requests by residents and community groups in the affected areas with the ultimate purpose “to improve traffic safety and enhance traffic flow,” according to the board letter.

“Residents make suggestions, as they could and should, with what they observe, and then a traffic study is done to see the merits of what they’re observing, and in this case, there was a justifying rationale for establishing a speed limit,” said Frasher.

The changes fall under the county’s strategic plan goals, “Make Environmental Sustainability our Daily Reality,” which “supports a clean, flexible and integrated multimodal transportation system that improves mobility and traffic safety.”

The appropriate signages are slated to be installed within 12 weeks of the supervisors’ adoption Tuesday.