The phrase "driving seat" means being in a position of control or power to make decisions and influence outcomes. It is metaphorical, often used to describe someone who is leading or in charge of a situation. Full definition
I would need a proper driving seat and steering wheel. (speedsportlife.com)
48 ′ 0 — 2 Cristiano Ronaldo was on target again just after the half time to put the game to bed and put Real Madrid in driving seat going into the last week of the season. (totalsportek.com)
In a lay - by on the western side of the Triangle I pull over to swap driving seats with Wallace. (evo.co.uk)