Which of the following bid documents contains additional or supplemental information to the design documents?

The bid document that contains additional or supplemental information to the design documents is the addendum. Addenda are issued during the bidding phase and serve to modify or clarify information contained in the original bid documents, including the design documents. They can include responses to questions from bidders, changes due to unforeseen issues, or any other type of clarification that may be necessary for bidders to understand the scope and requirements of the project fully.

Incorporating addenda ensures that all bidders have access to the same updated information, which helps maintain fairness during the bidding process. This is critical for ensuring that all proposals are based on the same understanding of the project requirements.

While the other choices involve important elements of the bidding process, they do not specifically provide additional information regarding design documents. The instructions to bidders outline the process and requirements for submission; the alternate usually refers to options for pricing or schedule alternatives; and the general conditions define the relationship and responsibilities among the parties involved in the contract, but none specifically serves to modify or supplement the design documents in the way an addendum does.