Ida-clear4783-1 PM 03-26 Dent Bridge Road Pavement Memo

158377846

MEMORANDUM

Western Federal Lands Highway Division
610 E. Fifth Street
Vancouver, WA 98661

DATE:

January 16, 2026

TO:

David Arena, Project Manager
Thinh Phan, Designer

FROM:

Jason Dietz
Pavement and Materials Engineer

SUBJECT:

Final Pavement Memo (PM 03-26)

signed by
JASON M Digitally

JASON M DIETZ

Date: 2026.02.24

DIETZ

08:01:08 -07'00'

Dent Bridge Road Rehabilitation Project

ID FLAP CLEAR 4783(1)

Clearwater County, Idaho
To support developing 95% PS&E plans for this project, we are submitting our final pavement recommendations for the project ID FLAP CLEAR 4783(1). The project site encompasses a paved, rural two-lane, first 5-mile-long asphalt concrete roadway (MP 0.0 to MP 5.0) of Dent Bridge Road. Dent Bridge Road is a 15-mile-long route that connects Orofino, Idaho to Dent Bridge and the city of Elk River, Idaho. It provides access to Dworshak Reservoir, campgrounds, recreation trails, Canyon Creek, and the Clearwater National Forest. The road serves for a variety of users including adjacent communities, truckers, hikers, snowmobile riders, bikers, hunters, campers, ATV riders, fisherman, tourists, and equestrians. The project scope includes rehabilitation of the existing asphalt concrete pavement surface, ditch cleaning throughout, deep patch, and sections of existing guardrail which are structural deficient and improperly placed.
Recommendations for rehabilitation of Dent Bridge Road were provided based on field investigations conducted in June 2021, subsurface exploration conducted in April 2022, and December 2025 in which ground penetrating radar (GPR) was used to detect asphalt pavement thickness of MP 0.0 to 6.0 and measure every 0.5 mile. We also measured width of pavement striping every 0.5 mile due to the centerline strip not reflecting center of roadway. It was also noted that asphalt concrete pavement was fairly new just prior to MP 1, MP 5.0 to MP 5.4, and MP 6.0 to MP 6.2 that might have been caused by slide repairs. Right before MP 5.0 lies an intersection that would be a good stopping point if the work needed to tie in past the intersection to make a future connection. Safety edges for this project would not be needed due to shoulder drop offs but could be if millings were used to make up these drop offs.

Traffic Data and Design Analysis

A final pavement recommendations report was provided by Nassim Sabahfar on July 13, 2023, in which she provided information for a pavement evaluation field visit conducted in June 2021, subsurface explorations conducted in April 2022, the result of tests conducted on