Formal sealed bids are opened in the Purchasing conference rooms at 2 p.m. Each Monday unless otherwise stated in the specifications.Invitations to bid (ITB), requests for bids (RFB) and pre-qualification notices in Texas, Tarrant County, page 1. Your profile contains the information available to general contractors when they are inviting subcontractors like you to bid. Information on current Bids and Request for Proposals can be accessed through Public Purchase. Contractor prequalification. TxDOT must qualify bidders to become eligible to bid or to receive a bid proposal on a construction or maintenance project. Prospective bidders must register with the procurement website as a plan holder, even if contract documents are obtained from a plan room or other site. Our certified estimators provide construction estimating services Tarrant County TX to help contractors increase their bid-winning ratio.