Some Good News For Motorists This Week. Gas Prices Are Declining After The Price Of Crude Oil Plunged. Tennessee Gas Prices Dropped Two Cents, With The State’s Average $2.39, Which Is Nine Cents Lower Than Just A Month Ago. Meanwhile, Johnson City Drivers Are Paying On Average $2.42 This Week. Nationally, Motorists Are Paying On Average $2.58 This Week.