The new I-66 Express Lanes Interchanges will be at
Century Park Dr and
University Blvd whenever they open with the expanded Express Lanes Outside the Beltway. (tentatively 2022).
EDIT (12-29-2021): At that time, points should potentially be added on US 29 at University Blvd, Stringfellow Rd, and Monument Dr. The latter two already directly connect to I-66. Vaden Dr seems to be unnecessary to add for US 29 and VA 237. (Points have been added to US 29 as of 6/29/2022.)