The prima facie limits are as follows and shall be applicable unless changed as authorized in this code and, if so changed, only when signs have been erected giving notice thereof:
(a)
Fifteen miles per hour:
(1)
When traversing a railway grade crossing, if during the last 100 feet of the approach to the crossing the driver does not have a clear and unobstructed view of the crossing and of any traffic on the railway for a distance of 400 feet in both directions along the railway. This subdivision does not apply in the case of any railway grade crossing where a human flagman is on duty or a clearly visible electrical or mechanical railway crossing signal device is installed but does not then indicate the immediate approach
of a railway train or car.
(2)
When traversing any intersection of highways if during the last 100 feet of the driver’s approach to the intersection the driver does not have a clear and unobstructed view of the intersection and of any traffic upon all of the highways entering the intersection for a distance of 100 feet along all those highways, except at an intersection protected by stop signs or yield right-of-way signs or controlled by official traffic control signals.
(3)
On any alley.
(b)
Twenty-five miles per hour:
(1)
On any highway other than a state highway, in any business or residence district unless a different speed is determined by local authority under procedures set forth in this code.
(2)
When approaching or passing a school building or the grounds thereof, contiguous to a highway and posted with a standard “SCHOOL” warning sign, while children are going to or leaving the school either during school hours or during the noon recess period. The prima facie limit shall also apply when approaching or passing any school grounds which are not separated from the highway by a fence, gate, or other physical barrier while the grounds are in use by children and the highway is posted with a standard “SCHOOL” warning sign. For purposes of this subparagraph, standard “SCHOOL” warning signs may be placed at any distance up to 500 feet away from school grounds.
(3)
When passing a senior center or other facility primarily used by senior citizens, contiguous to a street other than a state highway and posted with a standard “SENIOR” warning sign. A local authority may erect a sign pursuant to this paragraph when the local agency
makes a determination that the proposed signing should be implemented. A local authority may request grant funding from the Active Transportation Program pursuant to Chapter 8 (commencing with Section 2380) of Division 3 of the Streets and Highways Code, or any other grant funding available to it, and use that grant funding to pay for the erection of those signs, or may utilize any other funds available to it to pay for the erection of those signs, including, but not limited to, donations from
private sources.