The month of May is designated as "Drive Ohio Byways Month" because May is the start of tourism season in Ohio.
Ohio Rev. Code Ann. § 5.292
Drive Ohio Byways Month
Effective: September 28, 2018; Latest Legislation: House Bill 159 - 132nd General Assembly
Official source: Ohio Laws & Administrative Rules (Legislative Service Commission). Reproduced from public-domain Ohio statutes; confirm against the official source for the current text. Not legal advice.