while suicide is a possibility, it seems a rather strange way to go about it - why not just crash the car at 70mph? he'd likely still die, so why make the call and lie etc?
actually i suspect he had been clocked by a speed camera somewhere nearby and thought up this as an elaborate excuse to get out of whatever punishment might happen to a person going 119 on a motorway.
hes realised he might get a hefty fine, banned, or lose his licence or something and thought evidence of a police record of a 999 call, around the same time as the camera took the pic, would 'prove' his excuse that it wasnt his fault etc - would save him from any punishment.
clever in many ways i guess, not so clever that he tried to keep the speed up while on the phone etc.