ARB Locomotive Emissions Verifications and Technology Demonstrations

This page last reviewed March 1, 2016


This webpage provides information on both ARB locomotive emissions verifications and locomotive technology demonstrations.

ARB Locomotive Emission Verifications

The Air Resources Board (ARB) is responsible for issuing locomotive emission verifications (see below) to determine eligibility for: 1) 1998 Agreement Ultra-Low Emitting Locomotive (ULEL) credit, and 2) ARB incentive funding programs such as Proposition 1B, Carl Moyer, and AB 118 - Air Quality Improvement Program (AQIP).

ARB Verified Locomotive Technologies Eligible for Incentive Funding

Below are the Tier 4 locomotive technologies that are ARB verified and eligible for ARB incentive funding:

Below are the Tier 4 locomotive technologies that have been conditionally verified by ARB and may be eligible for incentive funding in the near future:

  • Caterpillar/Progress Rail (Cat/PR) Tier 4 Medium Horsepower Locomotive (on schedule for full verification mid-2016)

Key Program Links


ARB Locomotive Emission Verifications



Line Haul Locomotives


  • Caterpillar/Progress Rail Tier 4 Emission Level - Tier 2 engine repower with SCR and DOC Retrofits - on an older line haul locomotive to achieve Tier 4 emission levels - February 22, 2011

  • Miratech Diesel Oxidation Catalyst retrofit onto an older line haul locomotive - October 14, 2010

  • General Electric (GE) Locomotive SmartBurn Technology on new line haul locomotives - August 23, 2006

Genset Switch Locomotives

  • Brookville Equipment Company (BEC) - November 23, 2011 (BMEX 259)

  • Caterpillar/Progress Rail - April 6, 2010 (PR22) and November 24, 2010 (PR15B) 

  • Johnson Matthey (JM) - February 25, 2014
  • Motive Power (MP) - September 3, 2008, November 23, 2010

  • National Railway Equipment Company (NREC) - April 13, 2009 (UPY 2701)

  • Railpower (RP - now R.J. Corman) - January 25, 2011 (UPY 896)

Electric Battery Hybrid Switch Locomotives

  • Railpower Battery Hybrid "Green Goat" Switch Locomotive - March 2, 2006 (RPRX 2405)

Liquefied Natural Gas Switch (LNG) Locomotives

  • Morrison Knudsen (Now Motive Power) Liquefied Natural Gas (LNG) Switch Locomotive - May 24, 2010 (BNSF 1200)


Advanced Locomotive Technology Demonstrations

The Air Resources Board has funded and participated, with U.S. EPA and local air pollution control districts, in a number of technology demonstrations to determine the technical feasibility, potential emission reductions, costs, and cost effectiveness of advanced technology locomotives (see below) that can further reduce emissions in California.

  • National Railway Equipment Company (NREC)

    • Tier 4 genset switch locomotive (NREX 2015

      • Tier 4 NOx: 1.3 g/bhp-hr NOx.  Tier 4 PM: 0.03 g/bhp-hr.

    • AB 118 Demonstration

    • Cummins QSX15 engine with EGR (Exhaust Gas Recirculation) and DPF (Diesel Particulate Filter)

    • Demonstration at Richmond Pacific Terminal Railroad at Port of Richmond, CA

    • Project Manager: Bay Area Air Quality Management District

    • $529,810, Fiscal Year 10/2011

  • GT Exhaust (GTE)

    • Tier 4 PM Genset Switch Locomotive

      • Tier 4 PM: 0.03 g/bhp-hr. Existing Genset NOx: < 3.0 g/bhp-hr

    • AB 118 Demonstration

    • DPF retrofit onto an existing genset switch locomotive (BNSF 1284)

    • Demonstration at the BNSF Richmond Railyard in Richmond, CA

    • Project Manager: Bay Area Air Quality Management District

    • $270,190, Fiscal Year 10/2011, Status-Ongoing

    • Final Report June 2013 (PDF - 7.03MB)

  • Electro-Motive Diesel (EMD)

    • Tier 3+ Medium Horsepower Line Haul Locomotive with EGR and DOC (Diesel Oxidation Catalyst)/DPFs (UP 9900)

      • Tier 2+ NOx: 3.5 g/bhp-hr.  Tier 4 PM: 0.03 g/bhp-hr.

    • AB 118 Demonstration

    • $502,865, Fiscal Year 09/2010, Status-Phase 2 Field Demonstration Ongoing

    • Final Report of First Phase Demonstration (September 2012).

    • Sacramento Metropolitan AQMD (Air Quality Management District) funded two-year field demonstration from UP Roseville

    • Project Manager: Sacramento Metropolitan AQMD

    • Final Report August 2012 (PDF - 1.33MB)

  • Johnson Matthey (JM)

    • DPF retrofit onto an existing genset switch locomotive (UPY 2755)

      • Tier 4 PM: 0.03 g/bhp-hr.  Existing Genset NOx: < 3.0 g/bhp-hr.

    • AB 118 Demonstration

    • Demonstration at the UP Dolores Railyard in Carson, CA

    • Project Manager: Ports of Los Angeles/Long Beach

    • $346,178, Fiscal Year 09/2010, Status-Ongoing

    • Final Report December 2013 (PDF - 9.1MB)
  • Caterpillar/Progress Rail (Cat/PR)

    • Demonstration of a Tier 2 engine repower with SCR (2nd generation) and DOC retrofits to achieve Tier 4 emission levels (PRLX 3004)

      • Tier 4 NOx: 1.3 g/bhp-hr. PM: 0.03 g/bhp-hr.

    • U.S. EPA Emerging Technology Grant ($1.2 Million)

    • Demonstration at the Arizona and California Railroad in Parker, Arizona.

    • Project Manager: Mike Jaczola - ARB

    • Final Report Pending

  • Caterpillar/ Progress Rail (CAT/PR)

    • Tier 2 engine repower with SCR (1st Generation) and DOC retrofits to achieve Tier 4 emission levels - (2009-2010) (PRLX 3004).

    • ARB Partial Funding

    • Demonstration at the UP Colton Railyard in Bloomington, CA

    • Project Manager: Mike Jaczola - ARB

    • $585,000, Final Report Issued May 2011

    • Final Report (PDF - 3.04MB)


Other Helpful Links



Please contact Michael Jaczola, Staff Air Pollution Specialist, at (916) 327-5607 if you have any questions about ARB locomotive emission verifications or demonstration programs.