While drivers are free to drive how they like, remember that deliveries have two catagories: Real and Race. Real is the board I prefer, so if you want to push that, then here are some details.

Restrictions for Users: 20: Job deliveries are divided into statistics according to the maximal reached speed. If the User wants their job delivery to be included in the "real" statistics, they may not exceed the speed of 100 kph (62 mph) in ETS2 or 130 kph (80 mph) in ATS, otherwise it will be included in the "race" statistics. The maximal allowed speed during active job delivery is 180 kph (112 mph). If this speed is exceeded, the job delivery will not be included in the statistics at all. Furthermore, the accepted distance of the job delivery may be no longer than 1.25 times the planned distance and no more than 1000 km (621 mi) longer than the planned distance, and in the current month a maximum of two deliveries initiated in the previous month can be accepted with up to 5000 km (3107 mi) of driven distance.