Updated March 4, 2022
Locomotive Idling, Air Quality, and Blocked Crossings
When a train is not moving but its engines are running, it
Selected Recent Blocked Crossing Incidents
can present risks and disruptions for the surrounding
There are no national statistics on the frequency or severity
community. Locomotives emit fuel exhaust that degrades
of blocked crossings, but recent incidents have received
air quality and generates noise and vibrations. If the idling
media coverage:
train is stopped at a highway-rail grade crossing, local road
transportation could be significantly impacted, especially if
November 2021: a Norfolk Southern train blocked
the nearest open railroad crossing is not close by. This
several crossings in the West End neighborhood of
could create serious conditions if first responders are unable
Birmingham, AL, for six days for unspecified reasons.
to reach emergencies on the other side of the tracks.
June 2018: a Canadian National Railway (CN) train
Why Do Locomotives Idle?
broke down in the town of Barrington, IL, blocking all
Train engines generate thousands of horsepower and take
four railroad crossings in the town for nearly an hour.
an hour or more to warm up before they can start pulling
Ambulances transporting victims of a highway collision
rail cars. This is one reason there is reluctance to turn them
were delayed in reaching the hospital. (Their injuries
off. Also, particularly relevant for a locomotive attached to
were non-life-threatening.)
a train, the brakes on the cars in the train do not work
without power. The locomotive must run to keep the air
April 2017: Senator Charles Schumer and then-Ulster
pressure brakes on a train applied (the equivalent of
County Executive Michael Hein called on CSX to
keeping a car in park). In temperatures below 40 degrees
resolve issues of trains idling at crossings in Kingston,
Fahrenheit, the engine has to be kept warm for engine fluids
NY, which cuts off certain businesses from the rest of
to work properly, as antifreeze cannot be used in
the city entirely if they are located on dead-end streets.
locomotive engines. Engines are also kept running to
provide air conditioning or heat for the crew, which may be
Possible Responses to Locomotive Idling
aboard even if the train is idling in a yard.
Technology to Reduce Idling Noise/Emissions
Why Do Trains Block Crossings?
The Environmental Protection Agency (EPA) has the
When trains are moving at different speeds or in opposite
authority to regulate locomotive engine noise under the
directions along a single-track rail line, one train will
Noise Control Act (42 U.S.C. §4916) and limit emissions
usually have to wait on a side track or on the nearest two-
under the Clean Air Act (42 U.S.C. §7547). In a 2008
track segment until the other train has passed; if a road
rulemaking (73 Federal Register 37096), EPA set stricter
crosses these tracks, the crossing will be obstructed until it
emissions requirements for locomotive engines built or
is safe for the train to proceed. In many cases, these waits
remanufactured after 2012. It also required new
are planned and meant to be brief, but unforeseen delays
locomotives to be equipped with an automatic engine
due to an oncoming or passing train can mean a stationary
start/stop system (AESS) that will shut down the engine
train must remain in one place for an extended period.
after 30 minutes of idling.
Railroad crews, bound by hours-of-service limits, may not
be permitted to move the train, which then must wait until a
A second device, called an auxiliary power unit (APU), is a
fresh crew can relieve them. Railroads try to schedule crew
small engine that can keep the locomotive’s main engine
changes in convenient locations, but service disruptions
warm, the batteries charged, and the brakes applied and
occasionally make this impossible, forcing trains to stop
therefore allow the main engine to be turned off without
midway through a journey. Train stoppages are also
endangering the crew or the equipment. An AESS can be
sometimes caused by mechanical failures.
programmed to trigger an APU automatically, without
requiring a rail worker to activate the locomotive on/off
Once a train has been idle for over four hours, or if any cars
switch. EPA opted not to require the use of APUs in the
were removed or added while stopped, regulations require
2008 rulemaking. However, the emission cap regulations
crew to perform an air brake test prior to proceeding to the
offer a fairly strong incentive to install them (40 C.F.R.
next destination, a process that can take several minutes.
92.132(a)(4)).
Freight trains can reach lengths of two miles, meaning it
EPA does not have authority under the Clean Air Act to
can take several minutes to completely pass a crossing even
require APUs or AESSs to be installed on existing
when rail traffic is moving. Where equipped, warning lights
locomotives. To require railroads to install idle reduction
or gates will engage some time before a train reaches a
equipment on all existing locomotives, which typically have
crossing and will remain engaged for some time after a train
service lives of 40 years, it would be necessary to either
has passed, somewhat prolonging the traffic obstruction.
enact freestanding legislation or amend the Clean Air Act.
https://crsreports.congress.gov
Locomotive Idling, Air Quality, and Blocked Crossings
Surface Transportation Board Remedies
in the Don’t Block Our Communities Act (D-BLOC, H.R.
The Surface Transportation Board (STB) reviews the
3698), creating permanent data collection requirements for
construction of new rail lines and transactions involving
railroads and the U.S. Department of Transportation (DOT),
existing lines. STB can impose environmental mitigation
but these were not enacted.
measures, including those related to locomotive idling, as
part of this review process. For instance, when CN acquired
State Laws Regarding Blocked Crossings
the so-called “J” Line around Chicago in 2008, STB
There are no federal laws or regulations specifically
recognized that a moderately used shortline railroad would
concerning highway-rail crossings blocked by trains.
become a heavily used main line track. STB, after a review
According to a 2013 report compiled by FRA and
from its Office of Environmental Analysis, required CN to
subsequent research conducted by CRS, 40 states and the
take a number of measures to mitigate the adverse impacts
District of Columbia have laws in effect regarding
of increased train traffic on local communities. These
obstructed crossings. Many of these set a time limit on
included
trains to occupy crossings, ranging from as little as five
minutes to as much as 20 minutes. Other states do not
construction of two road overpasses to eliminate
impose a statewide time limit but shield railroad employees
blocked crossings at heavily trafficked locations;
who block crossings based on orders from their supervisors.
accelerated acquisition of new locomotives that would
However, state and federal courts have generally found that
meet EPA emissions requirements for idling reduction
these laws are preempted by one or more federal laws,
systems and new procedures to shut down locomotives
rendering them unenforceable. The Federal Railway Safety
when not in use and when temperatures are above 40
Act of 1970 grants states the ability to enact their own rail
degrees; and
safety laws only if neither DOT nor the Department of
Homeland Security has issued regulations “covering the
measures to keep railroad noise below a certain level for
subject matter of” the state law. Moreover, the Interstate
nearby residents by constructing berms or installing
Commerce Commission Termination Act of 1995 further
vegetation along the tracks.
restricts states from enacting laws that regulate rail
transportation. Railroad companies have successfully
Possible Responses to Blocked Crossings
argued in court that laws setting time limits at crossings are
functionally the same as regulating railroad business
2006 Blocked Crossings Study
practices such as train length and speed or infrastructure
Under a 2005 law, the Secretary of Transportation was
construction, which states are not permitted to do.
tasked with undertaking a study of the impact of blocked
highway-railroad grade crossings on emergency responders.
The D-BLOC bill would have established a federal 10-
The final report, published in August 2006 by the Federal
minute time limit for blocked crossings (with exceptions),
Railroad Administration (FRA), noted that there is no
subject to civil penalties. These measures were passed by
uniform national data collected on blocked crossings or on
the House but not retained for final passage within IIJA.
emergency responder delays.
Grade Crossing Improvements
The report recommended forming close relationships
One effective but expensive way to resolve the issue of
between the railroad and the community so that each may
blocked crossings is to construct grade-separated
be made aware of the other’s concerns. In particular, if the
over/underpasses so that rail traffic does not interfere with
railroad is aware of the locations of critical public safety
road traffic. The 2015 surface transportation law, the FAST
facilities, such as fire and ambulance stations, it may be
Act, added “projects at grade crossings to eliminate hazards
able to adjust the location at which trains stop in order to
posed by blocked grade crossings due to idling trains” in
ensure a nearby grade crossing is not blocked. There are
the list of approved uses for the “Section 130” highway-rail
some actions railroad companies can take in order to
crossing safety program, which receives over $200 million
minimize time spent at crossings, including shortening
per year. These funds are then allocated to states by a
trains or building additional infrastructure. However, the
formula that slightly favors states with a disproportionately
general tendency has been for railroads to run longer trains
large share of public grade crossings.
for economic reasons, which may lead to lengthier delays at
grade crossings and more blocked crossings when a train is
Certain grade separation projects are also an eligible use of
stopped. Railroads can also adopt a policy of creating a gap
funds from the Rebuilding American Infrastructure with
in a stopped train so as not to block a crossing, though the
Sustainability and Equity discretionary grant program,
process of creating the gap is time-consuming and would
known as RAISE (formerly TIGER and BUILD), and from
require the crossing to be closed for that time.
the Consolidated Railroad Infrastructure and Safety
Improvement program, both administered by DOT. In IIJA,
FRA launched a website to collect blocked crossing
in addition to funding these programs, Congress created and
information from the public on a voluntary basis in 2019.
funded a new railroad crossing elimination grant program
The Infrastructure Investment and Jobs Act of 2021 (IIJA,
specifically intended to eliminate highway-rail grade
P.L. 117-58) directs FRA to establish a blocked crossing
crossings that are frequently blocked by trains.
portal to collect and analyze blocked crossing data for a
period of three years. An earlier proposal for IIJA passed by
Ben Goldman, Analyst in Transportation Policy
the House (H.R. 3684) contained measures, first introduced
IF10978
https://crsreports.congress.gov
Locomotive Idling, Air Quality, and Blocked Crossings
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 | IF10978 · VERSION 4 · UPDATED