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1 The purpose of this Guide is to provide transportation agencies with guidance in dealing with practical issues of selecting and managing access along truck routes, while improving traffic operations and safety. In this Guide, the term truck route applies both to routes that are formally designated by a transportation agency to serve trucks and to any other routes that carry a substantial volume of trucks. The formal designation of truck routes is a key operational and planning activity that should consider the truck demand volumes, the origins and destinations of truck shipments, and the suitability of particular roads and corridors to accommodate trucks of specific sizes. Planning for truck routes includes consideration of land use, roadway func- tional classification, strategic freight corridors, interagency collaboration, truck delivery needs, and site layout and internal circulation. A key aspect of planning is the position of each roadway in the transportation network, including the hierarchy of roadways and the freight function of each roadway. For example, Interstate highways and strategic corri- dors serve state-to-state and regional commerce; other roads serve as connections between freight activity centers and strategic corridors; while still other roads serve as distribution routes to deliver goods to markets. Trucks are an important consideration in the design and access management of roadways. Trucks are substantially larger than passenger cars, and their size needs to be a factor when designing geometric elements of the roadway and selecting access management treatments for the roadway. The length of trucks is a key consideration when selecting an appropriate storage length for turn lanes and intersection spacing. The height of trucks is an important factor in designing (and signing for) bridge clearances, particularly when accommodating oversize/ overweight (OSOW) vehicles. Where trucks are expected to use a driveway, particular consid- eration should be given to truck needs when designing various elements of the driveway, such as throat length and width, driveway profile, curb termination treatment, curb return radius, and driveway operation (e.g., one-way versus two-way, right-in/right-out). Trucks also have quite different operating characteristics than passenger cars. They take longer to accelerate from a stopped position and decelerate to a stopped position. Turning maneuvers are also a key challenge faced by trucks, particularly on urban and suburban arterials. Where trucks make right turns at intersections, it is desirable to provide a curb return radius sufficiently large that a truck can make a right turn without encroaching on the curbline or on an adjacent or opposing lane. The movement of OSOW trucks generally requires operators to obtain a permit from the state department of transportation (DOT). Each state has its own rules about how permits are applied for and issued, how routes for OSOW trucks are determined, and what time-of- day or other restrictions may apply to OSOW truck movements. Routing considerations S U M M A R Y Design and Access Management Guidelines for Truck Routes: Planning and Design Guide
2 Design and Access Management Guidelines for Truck Routes: Planning and Design Guide generally include physical conditions, such as overhead structures, structural capacity of bridges, cross section widths, overhead traffic signals, and roundabouts. With the exception of some industrial and port locations, where the traffic stream may consist almost exclusively of trucks, very few roadway segments and intersections are designed solely to serve trucks. At most locations, trucks constitute only a limited portion of the motor vehicle traffic stream, and other travel modesâincluding automobiles, bicyclists, pedestrians, and transitâmust also be served. There are inherent conflicts between the needs of these various modes, such that designing solely for trucks might make travel inefficient or inconvenient for other modes. Thus, for the most part, roadways and inter- sections are not designed for trucks, but are designed to accommodate trucks, while also serving other travel modes. This Guide will help designers seeking an appropriate balance among travel modes that may vary substantially from corridor to corridor and from project to project. Included in the Guide are five case studies, which highlight truck-related challenges or concerns faced by transportation agencies, and the innovative strategies used by these agencies to mitigate the challenges or concerns.