In Jacksonville, we completed 7 vinyl-wrapped traffic signal cabinets in 2016 (artist Michelle Weinberg) and are currently in the design phase of another 5 more. 

I suggest 3-M vinyl product.

Our contract is not one that you would want to duplicate.

We had the artist manage the vendor, but sounds like you would be managing the vendor in your ambitious scenario. 

Here is part of the April, 2018 Call for the current project, which is a portion of the Downtown Investment Authority Urban Arts Project, Phase II:

Specific Artwork Information and Criteria:

Traffic Signal Cabinet Vinyl Wraps

5 artist-designed vinyl wraps: $6,000

Artist or artist team will create work to be digitally applied to vinyl to cover City-owned electric traffic signal cabinets. These cabinets are functional and are uniform in dimension. The artist will transform these utilitarian objects into works of art to enhance the visual landscape. The primary objective of this project is to initiate, promote, coordinate and implement surprise and to either make a loud statement or devise a camouflaging effect into the street environment.  Vinyl wraps may not interfere with the function of the traffic signal cabinet. Photographers, painters, graphic designers, fabric artists or 3-D artists are encouraged to apply, as the vinyl vendor will transfer the designs to vinyl wraps to create a piece of 3-D art.  If photographs of 3-D art will be used, both 3-D artist and photographer must apply as a team, with images of prior work samples of each. Any appropriate releases should be included. Artist must cover the cost of the vinyl vendor within the artist budget.

• Materials to include long lasting printed vinyl wrap material with anti-graffiti coating.  Paints of any kind are not permitted.
• Wrapping materials must be supplied and installed by a vendor who is to be approved at the design proposal phase and warrantied by manufacturer for at least 7 years. 3-M products are recommended.
• Vinyl vendors typically require designs to be submitted digitally, or submit designs to the vendor that are at least 11” x 17”, or submit larger works that can be scanned
• Artist must allow for the cost for the wrap vendor work. The Artist budget outlined is inclusive of the wrap vendor fee
• Designs or photographs may be similar but not repetitive
• Artist will be responsible for the completion of the installation by the vendor.
• Artist must be present during installation of the wrap.
• Reflective material may be allowed pending approval of COJ.

 Including photos below.

Good luck, 

Mason Martin