The Indiana Department of Transportation (INDOT) conducts chip seal operations on state highways to prolong the life of the road. The chip seal operation is labor, equipment and material intensive. A typical chip seal operation may involve 35 or more INDOT employees including truck drivers, flagmen, and equipment operators (brooms, rollers, aggregate spreader, and distributors).

This project was launched to better understand and document variations in how each of the six INDOT districts, approach the planning and execution of their respective chip seal operations. The goal was to identify areas in the operation where there were differences between districts and to determine best practices that could be shared among the districts.

Two observers joined the chip seal operations in all six districts. The observers spent a total of 10 days with the chip seal crews (2 days each with the crews from Fort Wayne, La Porte, Greenfield, and Seymour and 1 day each with the crews from Vincennes and Crawfordsville). One additional day was spent in Crawfordsville observing the Fog Seal operation that takes place a few days following chip seal.

During the initial phases of this project, many differences were observed regarding various aspects of the operation including the stone and equipment used, truck loading procedures, traffic control, and covering raised pavement markers (RPNs).

These observations were shared with key stakeholders on November 4, 2013 and with a second group of stakeholders on January 22, 2014. With the help of stakeholders, best practices were identified from the observations and a list of 14 recommendations was created to be shared across all districts. A series of meetings were then scheduled to share the recommendations with each district and to determine which recommendations they were interested in piloting.

The three ideas found during this project that provide the greatest opportunities for improving the overall operational efficiency of the chip seal operation are (1) the importance of closing roads during chip seal whenever possible, (2) the importance of choosing the best locations for stone stockpiles and oil tanker deliveries, and (3) the importance of fully loading dump trucks to their maximum safe and legal limit.

Report Number



chip seal, chipper, connector bar, stone, stockpile, oil distributor, trucks, downtime

SPR Number


Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, Indiana

Date of this Version