After A Four Month Drop, Gas Prices Have Been On The Rise Now For Four Weeks. The National Price For A Gallon Of Gas Stands At $2.28, While Tennesseans Are Paying On Average $2.12 Per Gallon This Week. Stephanie Milani With Aaa Auto Club Says The Price Of Gas Should Remain Fairly Stable For Awhile Now. Meanwhile, Tri Cities Motorists Are Paying On Average This Week $2.16 A Gallon, Up From $2.14 A Week Ago.