Office of Transportation EPA420-S-05-010 

and Air Quality September 2005 

Model State Idling Law 

Workshop — Atlanta, 

Georgia 

Meeting Summary 
EPA420-S-05-010 

September 2005 

Model State Idling Law Workshop —

Atlanta, Georgia

Meeting Summary 

Transportation and Regional Programs Division 

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency 

NOTICE

This Technical Report does not necessarily represent final EPA decisions or positions.

It is intended to present technical analysis of issues using data that are currently available.

The purpose in the release of such reports is to facilitate an exchange of

technical information and to inform the public of technical developments.
The U.S. Environmental Protection Agency (EPA) sponsored a meeting on June 16-17, 2005, in 

Atlanta, Georgia, to develop a model state idling law. Participants included representatives from 

states and local governments and the trucking industry. This document summarizes the views and 

opinions of the participants which do not necessarily represent official EPA policy, positions, or 

views. The purpose of this meeting was, among other things, to reach consensus on a model state 

idling law. EPA takes no position on state or local idling laws. EPA=s role in these meetings was 

that of organizer and facilitator only. 

i 
List of Issues 

A: Exemption for Traffic and Adverse Weather – Allow idling when a vehicle is forced to remain 

motionless because of traffic, an official traffic control device or signal, or at the direction of a law 

enforcement official. Also, exempt vehicles idling while waiting in a queue. Finally, exempt 

vehicle idling when adverse weather conditions affect the safe operation of the vehicle (e.g., 

operating defrosters, heaters, air conditioning) to prevent a safety or health emergency .............. 1 

B: Exemption for Emergency Vehicles – Exempt idling for police, fire, ambulance, public safety, 

military, and other emergency or law enforcement vehicles in an emergency or training mode... 1 

C: Exemption for Maintenance – Exempt idling of a vehicle when the primary propulsion engine 

is being operated for maintenance, servicing, repairing, or diagnostic purposes. Also, exempt a 

vehicle if idling due to mechanical difficulties over which the driver has no control.................... 2 

D: Exemption for Research and Development – Exempt a vehicle when the primary engine, 

vehicle, or device is engaged in idling testing operated by the manufacturers or their partners 

(including labs, research facilities, and trucking companies)......................................................... 2 

E: Exemption for Power Take Off – Exempt a vehicle when the primary propulsion engine is 

providing a power source necessary for mechanical or electrical operations other than propulsion 

such as loading or unloading, mixing or processing cargo, direct drive trailer refrigeration, or 

providing a mechanical extension to perform work functions ....................................................... 3 

F: Exemption for Transportation Refrigeration Units – Exempt any trailer with an independent 

engine used for the sole purpose of controlling cargo temperature................................................ 3 

G: Exemption for OEM Warm-Up and Cool-Down – Exempt the vehicle when the primary 

propulsion engine is idling to reach the manufacturer=s recommended operating temperature or 

idling to cool down the engine........................................................................................................ 3 

H: Exemption for Weather (Long Haul Trucks) – Exempt vehicles during certain weather 

conditions, both low and high temperature conditions................................................................... 4 

I: Exemption for Weather (School, Transit, Tour Buses) – Exempt vehicles during certain weather 

conditions, both low and high temperature conditions................................................................... 4 

J: Exemption for Required Inspections – Exempt the time required for a truck to pass through any 

State/Federal inspection where the engine must be idling to conduct the inspection .................... 5 

K: Exemption for Clean Vehicles – Exempt natural gas, electric, or hybrid vehicles .................. 5 

L: Motor Coach/Tour Bus/Passenger Bus Loading/Unloading..................................................... 5 

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M: Exemption for Mobile Idle Reduction Technologies – Exempt any mobile idle reduction 

technology (generator sets, auxiliary power units (APUs), direct fuel fired heaters) operating to 

provide heating, air conditioning, or auxiliary power to the vehicle.............................................. 6 

N: Exemption for Sleeper Berths – Exempt any truck with a sleeper berth for the time period that 

the truck driver rests/sleeps............................................................................................................. 6 

O: Penalties .................................................................................................................................... 7 

P: Outreach and Education ............................................................................................................ 8 

Q: Incentives .................................................................................................................................. 8 

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A 

Issue: Exemption for Traffic and Adverse Weather – Allow idling when a vehicle is 

forced to remain motionless because of traffic, an official traffic control device or 

signal, or at the direction of a law enforcement official. Also, exempt vehicles 

idling while waiting in a queue. Finally, exempt vehicle idling when adverse 

weather conditions affect the safe operation of the vehicle (e.g., operating 

defrosters, heaters, air conditioning) to prevent a safety or health emergency. 

Discussion: Discussion on this issue revolved primarily around the issue of defining traffic, as 

well as whether or not trucks queuing might be considered being stuck in traffic. It 

was suggested that traffic is when vehicles are stopped on the road, rather than 

off-road. It was also noted that this is usually beyond the control of the driver, so 

an exemption was favored. 

Consensus: Consensus was reached on the need for an exemption for vehicles stuck in traffic 

or due to adverse weather conditions, but there was significant disagreement on 

how to treat queuing. 

B 

Issue: Exemption for Emergency Vehicles – Exempt idling for police, fire, ambulance, 

public safety, military, and other emergency or law enforcement vehicles in an 

emergency or training mode. 

Discussion: There was minimal discussion on this issue, because most participants agreed on 

the need for this exemption. However, several suggestions were made. It was 

suggested that snow plows be included in this category and be given an exemption. 

 In addition, it was suggested that the exemption only apply to vehicles when they 

are in an emergency or training mode. For example, a fire engine parked at a 

grocery store while firemen/women are purchasing groceries would not be allowed 

to idle. Many participants believed that significant outreach to achieve voluntary 

compliance would be needed in this area because they felt that enforcement would 

not be likely against law enforcement or emergency personnel. 

Consensus: General consensus reached on this exemption, with suggestions to include snow 

plows and to allow the exemption only for vehicles in emergency or training mode. 

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C 

Issue: Exemption for Maintenance – Exempt idling of a vehicle when the primary 

propulsion engine is being operated for maintenance, servicing, repairing, or 

diagnostic purposes. Also, exempt a vehicle if idling due to mechanical difficulties 

over which the driver has no control. 

Discussion: Discussion focused on the second portion of the exemption which would exempt 

idling due to mechanical difficulties. Participants generally felt that this might be 

too vague, and might result in a large loophole that could be exploited, since law 

enforcement personnel would really have no way to tell if there were truly 

mechanical difficulties which prevented the driver from turning off the truck. 

Some participants suggested that a system could be set up in which the driver is 

given a ticket which would be dismissed later once proof of the repair was 

submitted. Alternatively, they suggested that a warning could be given the first 

time, with escalating fines for subsequent similar offenses as a way to reduce 

exploitation of this exemption. On the issue of the exemption for maintenance, 

servicing, etc., there was agreement that this was needed, but a suggestion was 

made to consider adding that this maintenance must be at “an official lab or 

facility.” 

Consensus: General consensus was reached on the first portion of this exemption for 

maintenance, servicing, etc. There was consensus on the need for an exemption for 

idling due to mechanical difficulties, but it was noted that states would need to be 

careful to avoid creating a loophole that could be exploited. 

D 

Issue: Exemption for Research and Development – Exempt a vehicle when the primary 

engine, vehicle, or device is engaged in idling testing operated by the 

manufacturers or their partners (including labs, research facilities, and trucking 

companies). 

Discussion: There was general agreement by participants on this exemption, and only minimal 

discussion. The majority of discussion was in relation to the possibility for fraud 

associated with the exemption, and how this could be prevented. It was suggested 

that states might want to consider requiring pre-notification of the authorities that 

testing or R&D would be taking place, or that some type of permit might be 

required in order to obtain the exemption. Some participants also believed that the 

phrase “is engaged in idling testing operated” should be deleted because it was not 

clear what this meant. 

Consensus: General consensus reached on this exemption, with suggestions as noted above. 

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E 

Issue: Exemption for Power Take Off – Exempt a vehicle when the primary propulsion 

engine is providing a power source necessary for mechanical or electrical 

operations other than propulsion such as loading or unloading, mixing or 

processing cargo, direct drive trailer refrigeration, or providing a mechanical 

extension to perform work functions. 

Discussion: Participants found this exemption important, and there was minimal discussion. 

Two suggestions were made. The first was to change the phrase “direct drive 

trailer refrigeration” to “straight truck refrigeration.” The second was to define 

idling in this exemption as “not doing useful work.” It was noted that some 

existing regulations define idling in this way, and in doing so distinguish it from 

power take-off applications. 

Consensus: General consensus reached on this exemption, with suggestions as noted above. 

F 

Issue: Exemption for Transportation Refrigeration Units – Exempt any trailer with an 

independent engine used for the sole purpose of controlling cargo temperature. 

Discussion: Participants noted that TRUs do not run with power generated by an idling main 

engine, but instead are essentially auxiliary power units. Therefore, it was 

questioned whether or not an exemption is actually needed, since no truck drivers 

would idle the main engine to provide power to a TRU, and therefore this law 

would not apply. Participants also noted that if there were a case where the TRU 

was actually operated with power from the idling main engine, this would likely be 

considered a power take off, and would be covered by that exemption. If the 

exemption is to remain, several wording changes were recommended: change 

“trailer” to “vehicle” and change “independent engine” to “engine independent of 

the propulsion engine”. 

Consensus: Many participants questioned whether this exemption is needed due to the fact that 

they do not believe TRUs would be covered by the law since they are technicaly 

APUs. However, if the exemption remains, several wording changes were 

recommended as discussed above. 

G 

Issue: Exemption for OEM Warm-Up and Cool-Down – Exempt the vehicle when the 

primary propulsion engine is idling to reach the manufacturer=s recommended 

operating temperature or idling to cool down the engine. 

Discussion: Most participants agreed that truck engines need a warm-up and cool-down period. 

The warm-up period will depend on the ambient temperature. The Engine 

Manufacturer=s Association informed EPA that they will provide OEM 

recommended warm-up and cool-down times for future meetings. The group 

talked about the need to pick a conservative estimate so law enforcement did not 

have to distinguish between different engine warm-up/cool-down times among the 

different engines. 

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Consensus: General consensus reached on this exemption, but pending more specific 

information from EMA. 

H 

Issue: Exemption for Weather (Long Haul Trucks) – Exempt vehicles during certain 

weather conditions, both low and high temperature conditions. 

Discussion: Discussion centered on whether or not it was reasonable and humane to expect 

truck drivers to rest or sleep in their trucks without the ability to use air 

conditioning or heat. Trucking representatives were generally strongly in favor of 

exemptions for driver comfort for both sleeper cabs and day cabs, indicating that 

often day cab drivers are forced to sit and wait in their trucks for long periods of 

time. There was also significant discussion about what incentives would be needed 

for truck drivers or trucking companies to invest in technologies that would reduce 

the need to idle in hot or cold weather. As in other meetings, trucking 

representatives pointed out that for truckers, their truck is their home, and not 

allowing them to idle for air conditioning or heating would be equivalent to 

regulating when home owners are allowed to use their heat or air conditioning. 

Representatives of government agencies acknowledged that this is a difficult issue, 

but also indicated the need to find a way to address this idling since it is probably 

the largest source of idling emissions from trucks. A suggestion offered and 

discussed at length was to provide exemptions for several years, after which the 

exemptions would “sunset” and be removed. This would give truck drivers the 

time to evaluate alternatives to idling, and to select and purchase necessary 

equipment. Some trucking representatives indicated that this would place an unfair 

burden on smaller trucking companies that do not have the monetary resources of 

larger companies, and in fact would force many of them to go out of business. 

Consensus: No consensus reached. All agreed that this was an important issue, and that 

enforcement of any temperature exemptions would be very difficult. 

I 

Issue: Exemption for Weather (School, Transit, Tour Buses) – Exempt vehicles during 

certain weather conditions, both low and high temperature conditions. 

Discussion: Discussion on this issue centered on the difficulties of regulating bus idling, given 

the different types and uses of buses, the differences in personal thresholds for heat 

and cold, travel patterns (county-to-county), and lack of alternatives. Participants 

were split concerning whether or not drivers should be allowed to idle buses, but a 

majority felt it was reasonable to idle for a limited time period if there were 

passengers on board. It was expressed though that if it is only the driver, he/she 

should look for an alternative to idling. There was also discussion on potential 

liability issues for municipalities and counties if passengers complain about 

problems relating to heat and cold if buses are not allowed to idle for passenger 

comfort. 

Consensus: One of the three groups felt that there should be no exemption for transit, school, 

or tour buses, but the other groups were unable to reach a consensus on the issue. 

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J 

Issue: Exemption for Required Inspections – Exempt the time required for a truck to pass 

through any State/Federal inspection where the engine must be idling to conduct 

the inspection. 

Discussion: All participants agreed that there was a need to exempt trucks during any State or 

Federal inspection, as well as during pre-trip and post-trip inspection. Several 

groups suggested that 5 minutes is typically sufficient to meet idling requirements 

of these inspections, and so this could be covered by the general idling time limit 

as long as it was at least 5 minutes, thereby eliminating the need for a specific 

exemption. One of these two groups, however, acknowledged that it may be 

beneficial to have this as a stand-alone exemption in case some states or localities 

do not adopt a general idling time limit of at least 5 minutes. 

Consensus: Consensus was reached on the need for this exemption, and 5 minutes was 

determined to be a sufficient amount of idling time. The need for a specific 

exemption will depend on the general idling time limit adopted. 

K 

Issue: Exemption for Clean Vehicles – Exempt natural gas, electric, or hybrid vehicles. 

Discussion: Most of the discussion centered on the need for an exemption, and whether or not 

granting an exemption would encourage the purchase of these types of vehicles, or 

would simply send the wrong message that idling is acceptable for certain types of 

vehicles. All agreed that no exemption is needed for electric vehicles, since they 

do not generate emissions directly when idling. Most felt that there should not be 

an exemption for natural gas and hybrid vehicles, because they still do consume 

fuel and would be generating unnecessary emissions if idling. 

Consensus: General consensus reached that this exemption should not be allowed. 

L 

Issue: Motor Coach/Tour Bus/Passenger Bus Loading/Unloading 

Discussion: Discussion on this issue was limited due to time constraints, but it was the general 

feeling of participants that idling for some amount of time during loading and 

unloading of passengers was reasonable, as long as it was not excessive. Most felt, 

however, that idling to heat or cool the vehicle prior to boarding, as opposed to 

during boarding, may not be necessary. 

Consensus: General consensus on the need to allow passenger buses an idling exemption only 

when passengers where boarding or disembarking. 

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M 

Issue: Exemption for Mobile Idle Reduction Technologies – Exempt any mobile idle 

reduction technology (generator sets, auxiliary power units (APUs), direct fuel 

fired heaters) operating to provide heating, air conditioning, or auxiliary power to 

the vehicle. 

Discussion: Discussion focused on whether or not it is appropriate for this to be listed as an 

exemption, since participants did not feel that an APU “idles,” and therefore it 

would not be covered under this law. It was felt that perhaps a more explicit 

definition of “idling” is needed if APUs are to be considered as idling. If they were 

to be included though, opinions were split on whether or not APUs should be 

exempted, primarily because after 2007, the assumption is that new diesel vehicles 

will generate fewer particulate matter emissions than most APUs. Suggestions 

were made that there could be an exemption for the use of APUs on all pre-2007 

model year trucks. Finally, some participants expressed concern on how to define 

a mobile idle reduction technology. 

Consensus: No consensus was reached, though in general participants agreed that APUs 

represent a major opportunity to reduce truck idling, and therefore they should be 

careful not to discourage companies from purchasing and using them. 

N 

Issue: Exemption for Sleeper Berths – Exempt any truck with a sleeper berth for the time 

period that the truck driver rests/sleeps. 

Discussion: There was significant discussion on this issue with most everyone agreeing that 

truck drivers need to be given the opportunity to remain comfortable. It was 

pointed out that this is not just an issue of comfort though, because if a truck driver 

cannot sleep well due to heat or cold, he/she will be tired the next day and may pose 

a safety hazard due to this fatigue. There was also agreement among all 

participants that whenever a truck is not occupied by the driver, it should be turned 

off as there is no reason to idle. Temperature limits above or below which idling 

would be allowed were largely dismissed as inappropriate, due to both difficulty in 

enforcement as well as differences in comfort thresholds of drivers. It was pointed 

out that a driver from the south may be very comfortable in an 85 degree Fahrenheit 

cab, but a driver from the north may find this very hot and uncomfortable. All 

participants agreed that mobile idle reduction technology seems to be the most 

appropriate method for reducing idling, and there was a discussion of allowing this 

exemption with a sunset several years in the future. This would allow truck drivers 

or trucking companies to identify alternatives to idling and to purchase any 

necessary equipment prior to the sunset of the exemption. There was also 

significant discussion about whether or not a similar exemption is needed for day 

cabs, since drivers often must sit and wait in these trucks in extreme temperatures 

as well. 

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Consensus: No consensus was reached, though there was agreement on a number of points. 

These included the need for better education of drivers, as well as incentives to 

reduce idling. There was also general agreement that mobile idle reduction 

technology mounted on the truck was going to be the most effective way to reduce 

long-duration idling of trucks with sleeper berths. 

O 

Issue: Penalties 

Discussion: Discussion focused on who should be held liable, the truck driver or the trucking 

company owner, and there were strong arguments for both. It was felt that fining 

the driver for violations would hold that driver accountable for his/her actions. On 

the other hand, fining the trucking company would provide an incentive for the 

company to provide training and idling reduction technologies on the trucks. Many 

felt that difficulty in recordkeeping might ultimately dictate who receives the fine. 

 There were also suggestions that both the driver and the company could receive 

notices and/or fines, and this would have the positive impact of encouraging both to 

change how they do things with respect to idling. There was also substantial 

discussion about situations in which drivers are idling while waiting at a facility to 

load or unload. Many felt that the distribution center should share in the liability if 

they are causing the drivers to wait due to some fault of the facility. It was agreed 

that this would be difficult to enforce, but participants encouraged EPA to consider 

this for the model law. Similarly, there was discussion about truck stops, and 

whether they should be held responsible for allowing trucks to idle on their 

premises. The trucking industry representatives were generally opposed to this, 

noting that truck stops provide a safe place for drivers to park and rest, and that 

truck stop owners are not responsible for driver idling like a terminal operator. 

Finally, there was discussion about the level of fines, as well as the benefits of first 

issuing a warning. There was a general agreement that an initial warning should be 

issued both to the driver and to the trucking company. For subsequent violations, 

there was no agreement on levels of fines, or whether the fines should escalate with 

each subsequent violation. 

Consensus: There was consensus that in some way, both the drivers and the trucking companies 

that employ the drivers need to be made aware of violations when they occur. 

There was no consensus though on who should ultimately pay a monetary fine, and 

so a solution was suggested in which both pay fines after receipt of an initial 

warning. Though not consensus, there was a general opinion voiced by participants 

that the penalty/fine structure should be kept as simple as possible. 

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P 

Issue: Outreach and Education 

Discussion: All agreed that no matter what the idling law would say, it will not be useful 

without effective outreach and education of drivers and trucking company 

representatives. A wide variety of options were discussed by participants for 

getting the word out both about the need to reduce idling, as well as about the 

provisions of the idling laws themselves. These options included: companies 

being required to have a written policy that is distributed to all drivers; drivers 

signing a formal company policy notification; distribution of flyers/brochures at 

truck stops, ports, distribution centers, terminals, toll booths, weigh stations, etc.; 

radio ads or programs; signage by the side of the road upon entering a state or 

jurisdiction with an idling law; training during CDL courses; and sending 

information with registration or tax documents. 

Consensus: There was consensus on the need for extensive and effective outreach and 

education in order for idling laws to have any significant positive impact. All 

agreed that more education was better and that this should take place through 

multiple avenues. 

Q 

Issue: Incentives 

Discussion: General discussions took place about incentives that would be effective in 

convincing drivers and trucking companies to try to reduce idling. Most felt that 

two important incentives were a weight waiver for trucks purchasing and installing 

mobile idle reduction technologies, and tax incentives for the purchase of mobile 

idling reduction technologies. Some noted that they had observed trucks parked in 

spaces equipped with truck stop electrification technology, but the trucks were not 

using the equipment. It was suggested that policies could be put in place by either 

the truck stops or the states that if you are parked in a space equipped with idle 

reduction technology, you must use that technology or vacate the space. Another 

suggestion was for more trucking companies to institute incentive plans for drivers, 

wherein drivers receive monetary or some other form of extra compensation as a 

reward for reducing idling. Finally, there was strong support for the concept of 

designated, reserved truck parking spaces for trucks that would not idle. The 

concept of a “SmartWay Rest Area” or “SmartWay Truck Stop” was endorsed by 

many participants. 

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