merit. Roadmaster seeks to invalidate the contract between itself and Calmodal as illegal, and therefore unenforceable, because Calmodal allegedly violated the Interstate Commerce Act by acting as a broker without a license. However, the Act provides a specific penalty for brokers operating without a license. See 49 U.S.C. § 14901(a) (providing that a person that “does not comply with section 13901 ... is liable to the United States for a civil penalty of not less than $500 for each violation and for each additional day the violation continues”). It is inappropriate to “add judicially to the remedies” by rendering a private contract void when a congressional statute provides specific penalties for violation. See Kelly v. Kosuga, 358 U.S. 516, 519, 79 S.Ct. 429, 3 L.Ed.2d 475 (1959) (<HOLDING>); Concord Industries, Inc. v. K.T.I. Holdings,
holding ban violated the sherman act recognizing that a unilateral contract can be formed when only one promise is illusory because the nonillusory promise can serve as an offer which the promisor who made the illusory promise can accept by performance holding that same activity violated  2 of the sherman act holding that a promisor may not avoid performing a legal promise because he elsewhere violated the sherman act holding that uniteds lease provisions violated  4 of the sherman act