Routine inspections are those regularly scheduled, performed, and recorded in accordance with all the procedures described in Chapter 8, Section 3 of this manual, Inspection Documentation and the Bridge Record, the TxDOT Coding Guide, and Specification for the National Bridge Inventory (SNBI). Conduct these inspections every twenty-four months for most bridges, and every forty-eight months for qualifying concrete culverts and span bridges. Some bridges need reduced inspection intervals when conditions warrant. Criteria for reduced and extended inspection intervals based on the requirements for risk-based inspection intervals outlined in 23 CFR 650.311 utilizing Method 1 inspection interval determination, which includes 48-month inspections of concrete box culverts, are provided later in this section. With the transition from the Coding Guide to the SNBI in accordance with 23 CFR 650.311, the collection and use of certain SNBI data is required to establish inspection intervals and to update and implement the reduced inspection interval policies by June 6, 2024. Prior to SNBI data collection TxDOT will utilize equivalent criteria per the Coding Guide to determine the reduced interval inspection.