Cowlitz - Dike Road

Project Number: 0819-01
From milepost 3.05 to milepost 5.32
RATA Funds: $1,692,000
Legislative District: 20
Status: PE and Design
Date Approved: 2019
Dike Road has experienced an increase in truck traffic due to the increased transportation of materials from the Port of Woodland dredge spoils site. Sand is being hauled along Dike Road north to Dike Access Road and on to I-5. The Port of Woodland needs to continue hauling to accommodate continued dredging of the Columbia River. Dike Road also serves agricultural, residential and recreational uses.
This section of Dike Road has numerous areas of recent pavement patching, alligator cracking and potholing caused by the increased truck traffic. Cowlitz County worked with Foundation Engineering, Inc. to investigate the pavement. The investigation revealed the asphalt pavement thickness varies from 2 to 7 inches over minimal gravel base. Over half the test locations had no gravel base.
It was determined that the most cost effective solution would be to create a cement treated base and pave over it. The cement treated base involves grinding the asphalt pavement and underlying material, treating with cement and water, and compacting. Based on anticipated truck traffic, the design structural section should be 5" minimum hot mix asphalt over 12" cement treated base.