Circulars Subscription

Please note: MSRP volumes are republished frequently, approximately every 2 years. New or amended standards between publications are announced via AAR Circular Letters. Therefore, to ensure compliance to the latest AAR standards, AAR Circular Letters must be monitored. The AAR Circular Letter system emails notices to all subscribers.

Circulars are a fee-based service provided by Transportation Technology Center Inc. in Pueblo, Colorado. Access Circulars at: https://www.aar.org/circulars