California Department of Transportation District 1
Caltrans > District 1 > Construction Projects > 197/199 Safe STAA Access > STAA: What you need to know
 

What are the issues? The 197/199 Corridor is very important for the movement of goods as Del Norte County has neither a railway nor a deep-water shipping port. The Del Norte County Local Transportation Commission, the Del Norte County Board of Supervisors and business community firmly believe economic viability is linked to STAA truck access on the Route 197/199 Corridor. This concern is supported by the fact the trucking industry has adopted STAA trucks as the universal standard for shipping. Lack of efficient STAA access would exclude Del Norte County from this trend and would result in negative economic impacts. In addition, some types of trucking (such as moving trucks) are federally exempt from STAA route restrictions and are using the Route197/199 Corridor already. How does Caltrans evaluate a route for STAA access? The route is evaluated using an engineering analysis tool that focuses on the actual swept path that the truck occupies as it negotiates each turn. If the swept path of the truck crosses onto the shoulder or into the opposing/adjacent lane, then it is “off-tracking”. Off- tracking is a condition of a turning movement where the rear tires follow a shorter path than the front tires. This off-tracking may cause the rear tires to track onto the shoulder or cross into the opposing/adjacent lane. How can this be corrected? • Widen the roadway where possible while minimizing environmental impacts. • Provide engineered larger radius curves. • Realign the roadway so that trucks approach any choke point at an optimal angle.