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