In the Spring of 2015, work began on Interstate 90 spanning between Mullan, Idaho and the Montana State border. Roadway construction began with the intent of having the westbound lanes completed by the end of 2015 and then reconstruction would begin on the eastbound lanes. Roadway reconstruction was the main focus; however there were quite a few upgrades involved. To minimize the amount of water build up on the surface of the road, the storm water drainage system would be upgraded as well as much needed repairs to the slopes of the roadway, which had substantial erosion damage. All of the existing metal guardrails and all of the road sign were to be replaced as well.
Among the much needed upgrades and reconstruction was the amount of concrete barrier that needed to be replaced. In addition, the existing barriers (the barrier wall separating the eastbound and westbound lanes) were to be replaced with taller median barrier. The long string of concrete barrier is made up of many smaller sections connected by a long headed steel pin or “barrier pin”. Although Idaho DOT has 3 different options for the connecting pin configuration, this project required 7,300 pins with a large forged round head as opposed to a welded plate. The standard Idaho pin dimensions for connecting barriers is 1-1/4” in diameter and 26” long. 4,600 of the required pins met the standard dimensions; however the replacement of the existing median barriers with the taller barriers required 2,700 of a custom length pin equaling 30”. In the end, the total weight of the required pins exceeded 75,000 pounds, packaged onto 25 pallets and required transport on two full flatbed trucks.