Below is a list of guidance I’ve researched on motorcycling within DoD and specific to Tucson
(I have copies of all of them.):

DoDI 6055.4, DoD Traffic Safety Program, 20 Jul 99
Para E3.2 Motorcycle Safety (HSPG Number 3); establishes the requirements we all should be aware of, specifically:
E3.2.7. Requirements for Personal Protective Equipment (PPE) are as follows: 
E3.2.7.1. The following PPE is mandatory for all persons as listed in paragraph 2.2. of the Instruction while operating or riding as a passenger on a motorcycle or ATV. 
E3.2.7.1.1. Helmets. Certified to meet Department of Transportation (DOT) standards properly fastened under the chin. If stationed outside CONUS and the host nation does not have an equivalent helmet standard, the helmet will meet the U.S. Department of Transportation standard. 
E3.2.7.1.2. Goggles and Face Shields. Impact or shatter resistant goggles or full-face shield properly attached to helmet. A windshield or eye glasses alone are not proper eye protection. 
E3.2.7.1.3. Sturdy Footwear is mandatory. Leather boots or over the ankle shoes are strongly encouraged. 
E3.2.7.1.4. Clothing. Long sleeved shirt or jacket, long trousers, and full-fingered gloves or mittens designed for use on a motorcycle. 
E3.2.7.1.5. Garment Visibility. A brightly colored outer upper garment during the day and a reflective upper garment during the night. Outer upper garment shall be clearly visible and not covered.

AFI 91-207, The US Air Force Traffic Safety Program, 1 Oct 95
Mostly paras 12, 13, 14.
Pretty much, it mirrors the requirements of DoDI 6055.4, with one significant additional restriction [I'd previously missed this difference, updating 23 May 04]:
Para 14, ...Brightly colored or contrasting vest or jacket as an outer upper garment...

AFI 91-207 / ACC Sup 1, 31 Jan 96: No reference to motorcycles.

AFI 91-207 / AETC Sup 1, 24 Aug 99
Unlike the ACC Sup, AETC’s addresses motorcycles extensively, some include:
Para A2.2.1.3 Prohibitions against borrowing or loaning motorcycles to unqualified operators;
Para A2.2.1.4 Mandatory riding equipment and apparel for motorcyclists on the installation and for military personnel off the installation (regardless of duty status);
Atch 3 Program Guidelines for Identifying High-Risk Military Motorcycles Operators.

AFI 91-207 / [DMAFB] BS1, 2 Aug 99
Section C -- Occupant Protection and Vehicle Requirements 14.  (Added)  Operator and any passenger must wear impact resistant goggles or a full-face shield on their helmet.  Exception for windshield is not authorized.

Section C -- Occupant Protection and Vehicle Requirements 14.  (*Added)  All motorcycle, motor scooter, and moped operations on Davis-Monthan AFB and for operations by military personnel off Davis-Monthan AFB include the wearing of a vest or jacket (bright white, red, yellow, orange or blue).  At night, the vest or jacket will have a minimum of 24 square inches of reflectorized material attached, clearly visible from the rear, not covered.

AFI 31-204, Air Force Motor Vehicle Traffic Supervision, 14 Jul 00
Para 3.2 Registration and Driver Requirements; includes ref to AFI 91-207.
Para 4.2.3.1 Motorcycles and mopeds; includes ref to AFI 91-207.
Para 4.2.3.2.5 Headphones and earphones; also addresses hearing protection.
Para 4.8.2 Parking; …MAJCOMs [or] installation commanders…should give special consideration to…motorcycle…parking.

AFI 31-204 / ACC Sup 1, 26 Mar 98 (Holdover—under review): No motorcycle reference.

AFI 31-204 / AETC Sup 1, 1 May 03
Again, contrasts with ACC’s Sup, as it addresses motorcycles several times;
Para 4.2.3.1 [Addresses requirement to operate on base] Note: Motorcycles will not be loaned to unqualified military or civilian personnel.  The owner is responsible for ensuring operators possess…

AFI 36-2903, Dress and Personal Appearance of Air Force Personnel, 29 Sep 02
Does not address motorcycles (with one irrelevant exception);
Chapter 3, Organizational Clothing and Equipment
Para 3.1 Organizational Clothing and Equipment. Organizations issue items listed in TA016.  The clothing remains the property of the organization…

AFI 36-2903 / ACC Sup 1, 25 Apr 97: Does not address motorcycles;
Para 7.2 Base Supplements must be approved by HQ ACC/DPPF prior to being published.

AFI 36-2903 / ACC ICs 03-1 and 03-2: Do not address motorcycles.

AFI 36-2903 / [DMAFB] BS1, 30 Dec 03
3.1.3.1.12.  Personal Protective Equipment (PPE) (Added).  Individuals will maintain the professional uniform standard while riding any two or three wheeled motorized vehicles on or off Davis-Monthan AFB.  All motorcycle riders (both driver and passenger) will wear a brightly colored vest with reflective material i.e., orange, red, green, or yellow over their clothing while the machine is being operated.  If a uniform is worn and an outer garment is required, individuals will wear one of the approved uniform outer garments, i.e., lightweight blue jacket, leather flight jacket, Gortex parka, cold weather parka, wet weather gear, the BDU jacket, or other approved uniform outer garment along with a safety vest.  A plain leather jacket (brown, black or blue) may also be worn but must maintain a proper military image and will not have any large logos or writing that would be offensive.  All PPE must be removed immediately after parking the vehicle.

Internet addresses:

Air Force Publishing
http://www.e-publishing.af.mil/

ACC Electronic Publishing
https://wwwmil.acc.af.mil/accpubs/

AETC Electronic Library
http://www.aetc.randolph.af.mil/im/series.html