### Clue: Gridlock on motorway going west — go east (7)
### Answer: IMPASSE 
 ### Explanation: Definition: Gridlock
 **Reversal of**(… going west, in an across clue) MI(M1 the north-south UK motorway, with the Roman numeral substitution) + PASS(go/move in a specified direction) + E(abbrev. for "east").
… yes, the other way.