As of this date, the map data is provided by HERE. You can check their map at wego.here.com and report an error by clicking on "feedback" located bottom right. Sometimes the error will be with their data, but sometimes the error will occur at Garmin.
The link provide by Bill_Murray will report the error to Garmin. I would recommend checking the wego.here map to see if it the error exists on their site. If the HERE map is correct, report it through Garmin and specify that the HERE map is correct and that the Garmin map is in error.
Thank you. Interestingly, the HERE map shows the exit as does Garmin and Mapquest, but not Google Maps. Odder still is that satellite view shows an exit. I've now sent an email to my riding buddies requesting confirmation that I am not mistaken about the exit location.
Figured it out! The exit was removed as part of a VDOT safety improvement project. According to the project details, that ramp would have been closed about a year ago. Google Maps got the memo, Mapquest and HERE did not. Perhaps Mapquest uses HERE maps??? I have reported it to HERE hoping to insure attention.