Problem is these types of select lists cannot be operated from the keyboard if they have an onchange handler that performs navigation. Why? Because the handler fires as the user moves the selection up and down using the keyboard. Moving through list items using the arrow keys will jump to another page or website location unexpectedly. This does not comply with WCAG 2.1 Guideline 3.2.2 – On Input (Level A).
SOLUTION: To make the select menu keyboard accessible, allow the user to trigger the navigation via a Submit button. This way the user has access to all the options in the menu using the up/down arrow keys, and, when ready, can press the Go (Submit) button that will trigger a processing script for successful navigation.
WEBSITE ACCESSIBILITY TESTING & REMEDIATION SERVICES: Mary Gillen is an experienced Website Accessibility Compliance Auditor and Remediator. She can test your website to determine if it meets accessibility standards:
WCAG 2.1: 312 checkpoints covering A, AA and AAA W3 accessibility guidelines
Section 508: 15 US federal guidelines covered by 59 accessibility checkpoints