This document is a quick-reference guide for suppliers who would like to submit a response to a solicitation via the APP Supplier Portal. How do I submit a bid or proposal?All formal bids and proposals shall be submitted as specified in the solicitation document. This tab discusses many of the steps you are likely to take while bidding as a subcontractor on ADOT projects. In a pre-bid meeting, the project specifications and any changes to the bid package are discussed. Browse Bid Opportunities.