SR 174 Safety Improvement In Nevada County

Project Facts

Description

This project proposes to realign several curves, widen shoulders, add a southbound left-turn pocket at Greenhorn Access Road intersection, and improve the Clear Recovery Zone (CRZ) on State Route (SR) 174 from Maple Way to You Bet Road, post mile (PM) 2.7 to PM 4.6 in Nevada County, California.

Purpose and Need

The purpose of this project is to improve safety and operations for all users. There have been a number of collisions along this segment of State Route 174 resulting in a collision rate that is higher than the state-wide average. The proposed improvements are expected to reduce collisions by improving roadway geometrics as well as the roadside recovery area in the event an errant vehicle departs from the roadway.

The current design standard for this type of highway requires 12’ wide lanes, 8’ wide shoulders, and with a 13 to 20 - foot CRZ beyond the lane line on each side of the highway. Existing lanes generally range in width from approximately 11 to 11.3 feet. Existing shoulders range in width from approximately 0.1 to 5.3 feet but are generally less than 1.5 feet wide. Fixed objects, such as trees and utility poles, are located within the Clear Recovery Zone. This section of highway also has curves requiring speeds of 30-35 MPH. The benefits of wider shoulders include:

enhanced pedestrian and bicyclist safety
additional room for an errant vehicle to recover and correct direction of travel
additional room off the traveled-way for emergency response vehicles such as fire trucks, ambulances, law-enforcement, tow trucks, etc.
additional room off the traveled-way for mail carriers, garbage trucks, newspaper delivery vehicles, etc.
additional room off the traveled-way for disabled or broken-down vehicles.