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September 20, 2017
Autonomous and Semi-autonomous Trucks
Introduction
While development of automated trucks faces many of the
Autonomous trucks potentially offer significant freight
same challenges as development of automated cars, such as
transportation savings for the U.S. economy. Trucks carry
cybersecurity for computerized control systems and
about three-quarters of U.S. freight when measured by
spectrum availability for communications, there are also
cargo weight or value. Driver compensation represents
unique issues. The weight of a fully loaded truck, at times
either the largest or second-largest cost component for truck
more than 80,000 pounds, makes the vehicle difficult to
carriers, depending on the price of fuel. Fuel and driver
control, especially at highway speeds. Shredded truck tires
compensation typically each account for about one-third of
are a common sight on highways; autonomous control
total operating costs. A truck driver may not drive for more
technology will need to be able to cope with tire blowouts.
than 11 hours per day under federal regulations, so it is
difficult for carriers to improve labor productivity except by
Economic factors will also affect the pace at which truck
using larger trucks. Also, because driver error is the
manufacturers install autonomous vehicle technology.
overwhelming cause of vehicle accidents, automation that
Manufacturers often customize trucks for specific
reduces accident rates could improve public safety.
customers, for example, and trucking firms are not likely to
invest in costly technology that may not function flawlessly
Despite the economic motivation, many in the trucking
in snow, ice, fog, and other difficult conditions. Insurance is
industry doubt whether driverless trucks are feasible in the
another significant cost element for trucking firms and their
foreseeable future given the current horizon of autonomous
customers; fully autonomous trucks are unlikely to be
technology. An alternative scenario, at least for the next
adopted until insurers offer them insurance rates no higher
decade or two, is that truck driver jobs may come to
than those for conventional trucks.
resemble those of airline pilots in that drivers would spend
part of their time monitoring an autonomous driving system
When considering the potential adoption rate of
rather than directly controlling the vehicle at all times. The
autonomous technology, it is important to recognize the
skills of truck drivers when backing up an 18-wheeler to a
different sectors of the industry. Autonomous technology is
warehouse or driving on local roads may be irreplaceable.
primarily geared toward long-distance tractor-trailer trucks,
In addition, some carriers may not be eager to forgo
as opposed to cement and dump trucks moving locally for
personal contact between drivers and customers, which may
construction projects or intra-city delivery trucks. The long-
create sales opportunities.
distance tractor-trailer segment is composed of companies
both with large fleets and with just one or a handful of
Automobile drivers may view driving ease and comfort as
trucks. Tens of thousands of such smaller carriers carry a
the primary benefits of autonomous technology. This is also
substantial portion of highway freight, but may lack the
relevant to trucking because exceptionally high driver
resources to install the latest equipment. Large fleet
turnover has plagued the industry. However, for motor
operators generally have the financial means to adopt new
carriers, the technology will primarily be judged on whether
technologies and may view doing so as an opportunity to
it can bring about cost savings.
gain advantage over smaller competitors.
Challenges to Autonomous Trucking
Truck Platooning
Deployment of autonomous trucks involves many
Although an autonomous truck delivering a load of beer in
technologies similar or identical to those being used to
Colorado received widespread publicity in October 2016, it
increase automation of passenger cars. (See CRS Report
appears that truck “platooning” is receiving more
R44940, Issues in Autonomous Vehicle Deployment, by Bill
widespread testing than fully autonomous trucking.
Canis.) Important technologies for trucking include
Platooning is a form of semi-autonomous operation that
could be a precursor to fully autonomous trucking.
automatic braking that uses cameras and radar to detect
Platooning involves one or more trucks following closely
objects in front of a truck;
behind a lead truck (see Figure 1), linked by wireless
communication. This configuration reduces wind
lane departure warning sensors;
resistance, thereby saving fuel (around 10% for a following
air disc brakes (as opposed to drum brakes) that allow
truck, 5% for the lead truck).
for shorter braking distance; and
All the trucks in a platoon have drivers, but only the driver
automatic transmissions, relatively new on heavy trucks,
of the lead truck is in full control of the vehicle. The drivers
that facilitate use of driver assistance technology.
in the following trucks steer their vehicles, but their feet are
off the accelerator and brake because truck speed is
controlled by wireless communication from the lead truck.
https://crsreports.congress.gov
Autonomous and Semi-autonomous Trucks
This communication reduces the braking response times of
intrastate motor carriers. Four agencies within the U.S.
the following trucks and therefore allows trucks to follow
Department of Transportation are the principal regulators of
closely enough to more significantly reduce wind
the trucking industry:
resistance. With this technology, braking among the trucks
in a platoon is essentially synchronized. A forward-facing
1. The Federal Motor Carrier Safety Administration
camera in the lead truck allows drivers in the following
(FMCSA) regulates truck drivers and trucking
trucks to see the road ahead of the lead truck, so that a
firms. This includes driver training requirements,
driver can disengage from the platoon if highway
limits on hours of driving, and safety inspections of
conditions make that desirable.
trucks on the road. Autonomous technology may
significantly change the qualifications required of
Figure 1. Truck Platooning
truck safety inspectors. In April 2017, FMCSA held
a public listening session to solicit information on
issues related to the design, development, testing,
and deployment of automated commercial vehicles
(see Docket No. FMCSA-2017-0114,
http://www.regulations.gov). The agency is
working on guidelines for allowing testing and
demonstrations of autonomous truck technology.
2. The National Highway Traffic Safety
Administration (NHTSA) regulates safety
equipment required on trucks, such as electronic
stability control and speed limiters. NHTSA
recently updated its policy document concerning
the testing and development of automated vehicles,
Source: CRS modification of figure from
which is also relevant to trucks (82 Federal
http://www.overdriveonline.com.
Register 43321, September 15, 2017).
3. The Federal Highway Administration regulates the
Synchronized braking requires that all trucks in a platoon
maximum weight of trucks on the Interstate
have good tires and well-maintained brakes. Poor road
Highway System and the allowable dimensions of
conditions, such as snow and ice, are still a safety concern.
trucks over a national network of truck routes. It
Platooning is most worthwhile on limited-access roads in
also overseas vehicle-to-infrastructure
flat, rural areas where trucks can travel at high speeds; the
communication as well as any other highway-
fuel savings are much less at low speeds. In principle, the
related infrastructure that supports autonomous
drivers of any properly equipped trucks traveling in the
vehicles, such as road markings and signs.
same direction could agree to platoon, but coordination
4. The Pipeline and Hazardous Materials Safety
problems complicate platooning by trucks under separate
Administration imposes additional safety
ownership: assignment of liability should accidents involve
regulations on trucks carrying hazardous materials.
platooning trucks from more than one trucking firm is
uncertain, and each company would prefer its trucks to
Legislation
follow rather than lead the platoon in order to enjoy greater
Congress is evaluating to what extent federal policy should
fuel savings. For this reason, platooning is likely to be most
assist autonomous vehicle technology by granting
attractive to large fleets that have sufficient and consistent
exemptions to certain federal requirements that otherwise
business over a given corridor.
would impede testing and demonstrations of these vehicles.
Congress is also considering preempting states from issuing
It is possible that platooning could evolve into a system in
certain regulations that are contrary to federal regulations or
which the first truck, with a driver at the wheel, leads a
contrary to other states’ regulations in order to avoid
number of driverless trucks. At the moment, however, most
differing state requirements.
tests appear to involve only one lead and one follower
truck; tests with multiple trucks and then driverless trucks
Whether to include trucks in autonomous vehicle legislation
lie in the future.
was debated during a hearing held by the Senate Commerce
Committee on September 13, 2017. The House-passed
Road tests of platooning first require that state laws
SELF DRIVE Act (H.R. 3388), which would establish a
prohibiting tailgating be waived. About 20 states are in the
regulatory framework for autonomous vehicle development,
process of developing rules allowing for tests of truck
specifically excluded trucks (§13(a)(1)(C)).
platooning, and several states have already done so.
The Federal Role
John Frittelli, Specialist in Transportation Policy
Federal regulation of trucking is focused on interstate
IF10737
trucking activity; states have more leeway in regulating
https://crsreports.congress.gov
Autonomous and Semi-autonomous Trucks
Disclaimer
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congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
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https://crsreports.congress.gov | IF10737 · VERSION 2 · NEW