3502 - 1 

(Adopted February 3, 2006) 

RULE 3502 MINIMIZATION OF EMISSIONS FROM LOCOMOTIVE 

IDLING 

(a) Purpose 

The purpose of this rule is to minimize emissions from unnecessary idling of a 

locomotive. 

(b) Applicability 

This rule shall apply to Class I freight railroads and switching and terminal freight 

railroads operating in the District. 

(c) Definitions 

(1) ANTI-IDLING DEVICE means a device installed on a diesel locomotive 

designed to automatically shut-off the main diesel internal combustion 

engine used for locomotive motive power after a specified time period 

when specified parameters (e.g., engine water temperature, ambient 

temperature, battery charge, railcar brake pressure, etc.) are at acceptable 

levels, and then automatically restart the engine when parameters are no 

longer at acceptable levels. 

(2) CLASS I FREIGHT RAILROAD means a Class I railroad, as classified 

by the Surface Transportation Board in 49 CFR Part 1201 Subpart A, that 

primarily transports freight rather than passengers. 

(3) CONTROLLING or LEAD LOCOMOTIVE means the locomotive within 

a consist of locomotives, including consists made up of switching 

locomotives and locomotives not connected to railcars, that is arranged as 

having the only controls over all electrical, mechanical and pneumatic 

functions for one or more locomotives. 

(4) DISTRICT means the South Coast Air Quality Management District’s 

geographical area of jurisdiction, as defined in California Health and 

Safety Code Section 40410 consisting of the four-county South Coast Air 

Basin and the Riverside County portions of the Salton Sea Air Basin 

(SSAB) and the Mojave Desert Air Basin (MDAB). The South Coast Air 

Basin, which is a subarea of the District, is bounded by the Pacific Ocean 

to the west and the San Gabriel, San Bernardino, and San Jacinto 
Rule 3502 (cont.) (Adopted February 3, 2006) 

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Mountains to the north and east and includes all of Orange County and the 

non-desert portions of Los Angeles, Riverside, and San Bernardino 

counties. The Riverside County portion of the SSAB and MDAB is 

bounded by the San Jacinto Mountains in the west and the Palo Verde 

Valley in the east. 

(5) EMERGENCY means any sudden, unexpected occurrence involving a 

clear and imminent danger, demanding immediate action to prevent or 

mitigate the loss of, or damage to, life, health, property, or essential public 

services. 

(6) IDLE OR IDLING OR IDLING EVENT means the operation of a 

locomotive’s diesel internal combustion engine(s) used for locomotive 

motive power during which the engine is not used to move the locomotive. 

It shall not be considered idling when the engine is operating while the 

locomotive is being slowed or moved by gravity. 

(7) LOCOMOTIVE means, for the purpose of this rule, a self-propelled piece 

of on-track equipment designed for moving or propelling railroad cars that 

are designed to carry freight or other equipment, but which itself is not 

designed or intended to carry freight, passengers (other than those 

operating the locomotive) or other equipment. The following equipment 

is not a locomotive: equipment designed for operation both on highways 

and rails; specialized railroad equipment for maintenance, construction, 

post-accident recovery of equipment, or repairs; and vehicles propelled by 

engines with rated horsepower of less than 750 kW (1006 hp). 

(8) LOCOMOTIVE CONSIST means a collection of two or more 

locomotives connected to each other. 

(9) LOCOMOTIVE ENGINE means the diesel internal combustion engine or 

engines incorporated into a locomotive or intended for incorporation into a 

locomotive and used to provide locomotive motive power. 

(10) MAINTENANCE OR DIAGNOSTIC PURPOSES means activities 

including repairs, testing and adjustment of systems, preventative 

maintenance, and associated activities such as problem troubleshooting, in 

which a mechanic is working on a locomotive to conduct such activities, 

excluding queuing before or after these activities. 

(11) OPERATOR means, for the purpose of this rule, a railroad responsible for 

operations associated with movement of freight within the District. 
Rule 3502 (cont.) (Adopted February 3, 2006) 

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(12) RAILROAD means, for the purpose of this rule, a commercial entity that 

operates locomotives to primarily transport freight. 

(13) SWITCHING AND TERMINAL RAILROAD means a non-Class I 

railroad engaged primarily in switching and/or terminal services for other 

freight railroads. 

(14) TAMPERED OR TAMPERING means for the purpose of this rule, the 

modification or disabling of an anti-idling device that would circumvent 

its normal operation such that even if specified parameters (e.g. engine 

water temperature, ambient temperature, battery charge, railcar brake 

pressure, etc.) are at acceptable levels, the main diesel internal combustion 

engine used for locomotive motive power will not automatically shut-off 

after a specified time period. 

(15) TRAILING LOCOMOTIVE means any locomotive in a consist of 

locomotives, including consists made up of switching locomotives and 

locomotives not connected to railcars, that is not the controlling 

locomotive. 

(16) UNATTENDED means where no crew member is on board a locomotive. 

(d) Idling Requirement 

(1) On and after August 3, 2006, unless a locomotive is equipped with an antiidling device that is set at 15 minutes or less, engaged, and not tampered 

with, an operator of a locomotive shall not idle an unattended locomotive 

for more than 30 minutes for any of the following reasons: 

(A) the crew of the locomotive consist has been relieved and the relief 

crew has not arrived; or 

(B) the crew of the locomotive consist has left for a meal; or 

(C) the locomotive is within the railyard; or 

(D) the locomotive is queuing for fueling, maintenance, or servicing; 

or 

(E) maintenance or diagnostics are being conducted on the locomotive 

that does not require operation of the engine. 

(2) On and after August 3, 2006, unless a locomotive is equipped with an antiidling device that is set at 15 minutes or less, engaged, and not tampered 

with, an operator of a locomotive shall not idle a trailing locomotive for 

more than 30 minutes for the following reasons: 
Rule 3502 (cont.) (Adopted February 3, 2006) 

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(A) the dispatcher or yardmaster notifies the operator of a delay that 

will exceed 30 minutes; or 

(B) there is a locomotive failure or breakdown that will result in a 

delay of more than 30 minutes. 

(e) Submittal of Emissions Equivalency Plan 

(1) In lieu of complying with the idling requirements pursuant to subdivision 

(d), at least 90 days before its intended use, the operator may submit to the 

Executive Officer and comply with the provisions of an Emissions 

Equivalency Plan for diesel particulate matter and oxides of nitrogen for a 

locomotive demonstrating that the locomotive will achieve equivalent 

reductions in emissions over a calendar year as will be required under this 

rule. The submitted Emissions Equivalency Plan shall: 

(A) identify the locomotive control technology(ies) to be implemented; 

(B) quantify locomotive emission reductions, demonstrating that: 

(i) there is no increase in total cancer potency-weighted 

emissions of toxic air contaminants; and 

(ii) the reductions are greater than or equal to the annual 

emission reductions that would be achieved by complying 

with paragraphs (d)(1) and (d)(2) 

(C) identify each locomotive(s) to be included; and 

(D) specify an implementation schedule; and 

(E) identify the mechanism(s) to be employed to ensure that emission 

reductions are enforceable for each locomotive. 

(2) The operator shall comply with idling requirements pursuant to 

subdivision (d) until the Executive Officer approves the Emissions 

Equivalency Plan. 

(3) Locomotives not included in an Emissions Equivalency Plan are subject to 

the following subdivisions of this rule: (a), (b), (c), (d), (h), (i), (j) and (k). 

(f) Approval of the Emissions Equivalency Plan 

Within 90 days of submittal of an Emissions Equivalency Plan pursuant to 

subdivision (e), the Executive Officer will approve or disapprove the Emissions 

Equivalency Plan. The Executive Officer shall approve the Emissions 

Equivalency Plan if it meets the requirements of subdivision (e). 
Rule 3502 (cont.) (Adopted February 3, 2006) 

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(g) Fees and Right of Appeal 

(1) The Emissions Equivalency Plan shall constitute a plan for the purpose of 

fees assessed under Rule 306 – Plan Fees. 

(2) The operator of a railyard may appeal the disapproval by the Executive 

Officer of an Emissions Equivalency Plan to the Hearing Board under 

Rule 216 – Appeals and Rule 221 - Plans. If the Hearing Board denies the 

appeal, the Emissions Equivalency Plan shall be revised, consistent with 

the findings and rulings by the Hearing Board and resubmitted within 90 

days after the Board’s decision. The revised submittal shall correct all 

deficiencies identified by the Hearing Board. 

(h) Circumvention 

(1) Tampering with an anti-idling device shall be considered a violation of 

this rule. 

(2) The moving of a locomotive for the purpose of preventing idling for more 

than the 30 minutes or to prevent an anti-idling device from shutting off a 

locomotive’s main propulsion engine shall be considered a violation of 

this rule. 

(i) Penalties 

Failure to comply with any requirement of this rule, or any provision of an 

approved Emission Equivalency Plan will result in a separate violation for each 

locomotive for each day of non-compliance and subject to penalties under Health 

and Safety Code Section 42400 et seq. 

(j) Exemptions 

(1) An operator is exempt from provisions of paragraphs (d)(1), (d)(2), and 

(d)(3) if the operator demonstrates the following conditions are met: the 

locomotive is being used in an emergency; or 

(2) ambient temperatures of 40o

F or lower occur or are predicted for the next 

24 hours in the area where the locomotive is operated; or 

(3) idling is required to maintain battery charge or voltage at a level sufficient 

to start the locomotive. 
Rule 3502 (cont.) (Adopted February 3, 2006) 

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(k) Severability 

If any provision of this rule is held by judicial order to be invalid, or invalid or 

inapplicable to any person or circumstance, such order shall not affect the validity 

of the remainder of this rule, or the validity or applicability of such provision to 

other persons or circumstances. In the event any of the exceptions to this rule are 

held by judicial order to be invalid, the persons or circumstances covered by the 

exception shall instead be required to comply with the remainder of this rule.