Curve realignment on Highway 20 above Nevada City intended to improve safety |

Curve realignment on Highway 20 above Nevada City intended to improve safety

A $55 million highway project to improve safety on Highway 20 is set to begin construction in fall 2021, Caltrans officials said.

Caltrans engineers were on hand Monday at the Eric Rood Administrative Center to show off the details of the project, which is slated to tackle two problematic sections of the highway above Nevada City: the curve at White Cloud campground and several curves on either side of Lowell Hill Road.

Caltrans plans to modify the alignment of the two non-contiguous segments of the highway, increasing the radius of the curves, widening shoulders to 8 feet, adding turnouts in both directions and improving the vertical grade. Additionally, the project will widen an existing turnout to standard width.

According to Caltrans, there were 14 accidents at White Cloud between January 2008 and January 2013, nine of which resulted in injuries. Between July 2009 and June 2014, drivers racked up 26 accidents in the Lowell Hill section of the highway, 18 of which caused injuries.

Lowell Hill Road residents Thomas and Robin Ziv were there to peruse the proposed improvements on the stretch of highway that borders their roadway.

“My question is, would the improvements cause people’s speed to increase?” said Robin Ziv. “People just drive that road too fast, especially in the winter.”

Thomas Ziv agreed, saying, “Once you get past White Cloud, it can get really iffy.”

The rate of accidents on those two stretches of Highway 20 is higher than the statewide average for similar roadways, said Caltrans Design Engineer Eric Souza.

“We monitor accident data and look at the safety index,” Souza said, adding the high accident rate appears to be about geometrics — how the roadway is set up, with the curve radius being too tight for the expected speed.

Caltrans will make those curves less drastic, he explained.

“The curve at White Cloud is a 30 mile-per-hour curve,” he said. “We did a high-friction surface treatment there at one time … But we think this will solve the problem permanently. We’re trying to stop the consolidation of accidents in (these) particular spots.”

Project approval and completion of environmental documents is slated for this May, with plan specifications and budget estimates due in April 2021. Construction is estimated to start in October 2021 and end in November 2023.

During the first year of construction, the new roadway will be built off the current roadway and should not affect traffic, said Project Engineer Candy Chiu. During the second year of construction, Caltrans will be connecting those new sections to the existing highway, using one-way traffic lanes and possibly weekend closures. Access will not be closed to residents along the highway.

Contact reporter Liz Kellar at 530-477-4236 or by email at

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