TC-1 Standard Road Plan Summary

This is a standard road plan document from the Iowa Department of Transportation (Iowa DOT) establishing traffic control requirements for work operations on roadways. The document provides specifications for traffic control measures applicable to slow-moving operation vehicles stopped on shoulders for less than one hour, requiring placement of 48" x 48" warning signs (W21-6 "Survey Crew" and W20-2 "Road Work Ahead") positioned 1,000 feet in the direction of traffic. For work lasting longer than one hour, contractors must equip all vehicles with amber revolving lights or amber strobe lights as appropriate. The plan emphasizes that all vehicles must be positioned as far from open traffic lanes as possible, utilizing entrances and driveways when parked, and that work operations must not interfere with traffic flow. This standard applies to two-lane or multi-lane roadways where work does not affect traffic and serves as a reference document for contractors conducting operations on Iowa roadways.

The document was revised on October 15, 2019, and includes references to additional Iowa DOT standard specifications (TC-402 and TC-202) accessible through the Iowa DOT design standards website. This plan is directly applicable to the related contract opportunity for installation of a new 240-foot by 12-inch diameter tile at US-30 in Story County, where contractors must implement these traffic control measures to maintain safety and traffic flow during the underground tile installation work scheduled for completion by December 15, 2026.