Alleviating Spaceport Traffic by Rewarding Operators Act of 2023 This bill allows the Department of Transportation (DOT) to establish a pilot grant program for projects to construct, repair, maintain, or improve transportation infrastructure and facilities for space launch and reentry sites. Launch and reentry site operators may use the grants for projects that (1) are located at, or adjacent to, a launch or reentry site; (2) directly enable or support transportation safety or transportation activities (i.e., the movement of people or property to, from, or within a launch site); and (3) are made generally available (subject to reasonable commercial terms). DOT may also issue a supplemental matching grant to an operator of a launch or reentry site.