AIM ¶ 4-3-20 — Standard Taxi Routes
AIM 4-3-20 explains Standard Taxi Routes (STRs): how pilots request them, ATC discretion, LOAs, LTAs, and pilot responsibilities for safe taxi operations.
In Plain English
Standard Taxi Routes (STRs) are pre-established, predictable taxi paths between two points on an airport's movement area. They reduce frequency congestion and streamline ground operations at busy airports.
STRs are made available two ways:
- Letter of Agreement (LOA) — ATC may assign the STR without a pilot request; the operator distributes updates to crews.
- Publicly-available — published on the FAA Domestic Notices website and announced via a Letter to Airmen (LTA) on the FAA NOTAM Search site.
To request a public STR, state your facility, callsign, location, and the STR name. Requesting an STR means you acknowledge full familiarity with it. Issuance is always at ATC's discretion.
Key pilot responsibilities:
- Stay current on STR versions and airport diagrams before accepting.
- Decline or ask for clarification if unsure — request a full taxi clearance instead.
- Advise ATC immediately if disoriented.
- Remember: an STR is not a runway crossing clearance and does not grant right-of-way.
- Do not request STRs during low-visibility SMGCS operations.
If ATC tells you to deviate from an STR, they must issue detailed taxi instructions for the remainder of the route.
AIM Source Text
FAA AIM ¶ 4-3-204-3-20. 4-3-20. Standard Taxi Routes
Standard Taxi Routes (STRs) provide a standard, predictable taxi route from an origination point to a termination point on the airport movement area. The use of STRs helps reduce frequency congestion and streamline taxi procedures. STRs may be available at certain airports. Absent an STR Letter of Agreement (LOA), issuance of an STR will be at the request of the pilot and discretion of ATC. STRs used under an LOA are issued by ATC and are not required to be requested by the pilot. STRs are available via two methods, (LOA) or publicly-available via the Domestic Notices website: https://www.faa.gov/air_traffic/publications/domesticnotices/ . An LOA for STRs will be revised for updates and changes, including cancellation on an as-needed basis with the operator. It is the responsibility of the operator to distribute changes to their flight crews. An STR may be requested by a pilot or assigned at the discretion of ATC to the pilot of an operator with an LOA STR. It is the responsibility of the pilot to request a full taxi clearance if not fully familiar with the STR. A Letter to Airmen (LTA) will be issued by airport traffic control towers to announce availability, updates, cancelation, or changes of publicly-available STRs with appropriate updates to the Domestic Notices website. An LTA may include an airport diagram. The airport diagram will be labeled “not for navigation” and is not an acceptable substitute for the most up-to-date airport diagrams. LTAs are available via the FAA NOTAM Search website: https://notams.aim.faa.gov/notamSearch/ . Pilots request publicly-available STRs by stating the desired STR name (e.g., ATC facility, flight or aircraft identification, location, request STR name). By requesting an STR, a pilot acknowledges full familiarity with the STR. The issuance of a pilot-requested STR is at the discretion of ATC. STRs contain the same characteristics and responsibilities: Pilots should not request, and ATC may not issue STR instructions during low visibility Surface Movement Guidance and Control System (SMGCS) operations. It is the pilot's responsibility to maintain familiarity and awareness of the most current versions of STRs, as well as airport diagrams and charts prior to accepting an STR assignment. If a pilot is unsure about the assigned STR procedure, the pilot is encouraged to either seek clarification from ATC or decline the STR assignment. Pilots who become disoriented during taxi should advise ATC immediately and request detailed taxi instructions or other assistance. An STR instruction does not constitute nor imply a clearance to cross a runway. Unless otherwise stated by ATC, the issuance of an STR does not give an aircraft the right of way over another taxiing aircraft. Unless otherwise instructed by ATC, originating from, and terminating to a non-movement area as part of an STR is at the discretion of the pilot in coordination with ramp control, if required. If ATC instructs the pilot to deviate from an STR, ATC must issue detailed taxi instructions for the remainder of the taxi. Pilots are urged to exercise caution when accepting STR assignments, especially when STRs are used or available at more than one airport in the same terminal area. ATC may cancel, amend, or revise an STR as necessary. Any updates to publicly-available STRs will be communicated via LTA with appropriate updates to the Domestic Notices website.
Oral Exam Questions a DPE Might Ask
Q1What is a Standard Taxi Route (STR) and what is its purpose?
Per AIM 4-3-20, an STR is a standard, predictable taxi route from an origination point to a termination point on the airport movement area, used to reduce frequency congestion and streamline taxi procedures.
Q2Does accepting or being issued an STR authorize you to cross a runway or give you right-of-way over other taxiing aircraft?
No. Per AIM 4-3-20, an STR instruction does not constitute or imply a clearance to cross a runway, and unless ATC states otherwise, it does not give the aircraft right-of-way over other taxiing aircraft.
Q3What should you do if you are unfamiliar with or unsure about an assigned STR?
Per AIM 4-3-20, it is the pilot's responsibility to request a full taxi clearance if not fully familiar with the STR. Pilots are encouraged to seek clarification from ATC or decline the STR assignment, and to advise ATC immediately and request detailed instructions if they become disoriented.
Related Paragraphs in AIM Chapter 4