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Open Access Publications from the University of California

Automatic Steering For Conventional Truck Trailers: Development and Assessment of Operating Concepts for Improving Safety, Productivity and Pavement Durability


Trucking productivity can be significantly increased by moving freight with longer combination vehicles (LCVs). However, LCV operations not only raise safety concerns for the surrounding traffic and the LCV drivers themselves but also can damage roadways and bridges not equipped to support the operations. All the discussion about truck size and weight limitations or about the pros and cons of LCV operations is predicated on the use of conventional tractors and trailers. We however observed that a root cause of several major issues associated with LCV operations is the problem of off-tracking. Through this one-year $58K project, we have demonstrated that this off-tracking problem can be drastically reduced with a new partial-automation technology: automated trailer steering (ATS).

ATS can provide safety benefit for all existing large-truck operations, including non-LCVs and LCVs. However, the degree of the benefit is difficult to assess. Perhaps a real potential of ATS lies in the expansion of LCV operations. Although ATS can reduce the cost of infrastructure modification, it may significantly increase the safety of LCV operations in denser-traffic areas or non-Interstate roadways. If nationwide LCV use is proven safe, the estimated total public cost for a 20-year planning horizon (excluding the undetermined trucking-company equipment-upgrade cost) will be $7,652 billion. Although the saving of $53 billion from the estimated total cost of $7,705 billion of a base case is less than 1%, the cost saving of $568 billion for shippers (from $4,980 billion to $4,412 billion) is almost 15%.

ATS can be used to create a new mode of operations in which a tractor can pull a larger number of short trailers - Shorter Trailer Combination Vehicles (STCVs). We demonstrated the benefit of STCV operations for the household-goods moving industry.

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