Section 22358.6 - Rounding speed limits in relation to free-flowing traffic(a) The Department of Transportation shall, in the next scheduled revision, revise and thereafter maintain the California Manual on Uniform Traffic Control Devices to require the Department of Transportation or a local authority to round speed limits to the nearest five miles per hour of the 85th percentile of the free-flowing traffic.(b) In cases in which the speed limit needs to be rounded down to the nearest five miles per hour increment of the 85th-percentile speed, the Department of Transportation or a local authority may lower the speed limit by five miles per hour from the nearest five mile per hour increment of the 85th-percentile speed, in compliance with Sections 627 and 22358.5 and the California Manual on Uniform Traffic Control Devices, as it read on March 30, 2021, if the reasons for the lower speed limit are documented in an engineering and traffic survey. The Department of Transportation or a local authority may also take into consideration Sections 22353, 22353.2, 22353.3, 22353.4, and 22353.5, if applicable.(c) In cases in which the speed limit needs to be rounded up to the nearest five miles per hour increment of the 85th-percentile speed, the Department of Transportation or a local authority may decide to instead round down the speed limit to the lower five miles per hour increment. If the speed limit is rounded down pursuant to this subdivision, the speed limit shall not be reduced any further pursuant to subdivision (b).(d) In addition to subdivisions (b) and (c), a local authority may additionally lower the speed limit as provided in Section 22358.7.(e) The total reduction in the speed limit pursuant to subdivisions (a) to (d), inclusive, shall not exceed 12.4 miles per hour from the 85th percentile speed.(f) Notwithstanding subdivisions (a) to (e), inclusive, a local authority may retain the currently adopted speed limit as provided in Section 22358.8 without further reduction, or restore the immediately prior adopted speed limit as provided in Section 22358.8 without further reduction.Amended by Stats 2022 ch 406 (AB 1938),s 2, eff. 1/1/2023.Added by Stats 2021 ch 690 (AB 43),s 6, eff. 1/1/2022.