Is the full or half diya obligatory, along with expiation and imprisonment, for a driver who hit and caused the death of a person, when the traffic court ruled that the accident was equally attributable to both parties?

If the error rate is 50%, then the 'Aqila (male agnates) bear half of the blood money on your behalf, and you are liable for a complete expiation, which is: freeing a believing slave. If you do not find one, then fasting for two consecutive months. Imprisonment is not required.