Del. Code tit. 21 § 404
In the absence of an agreement or arrangement with another jurisdiction, the Secretary of Transportation may examine the laws and requirements of such jurisdiction and declare the extent and nature of exemptions, benefits and privileges to be extended to vehicles properly registered or licensed or licensed drivers in such other jurisdiction, or to the owners of such vehicles, which shall, in the judgment of the Secretary of Transportation, be in the best interest of this State and the citizens thereof and which shall be fair and equitable to this State and the citizens thereof, and all of the same shall be determined on the basis and recognition of the benefits which accrue to the economy of this State from the uninterrupted flow of commerce.
21 Del. C. § 404