intransit REST Time

Hi

I have a shipment from A to B which takes 24 hours as per distance(1200 km) at 50km/hr.

I need to setup such that Vehicle should STOP in REST for every 8 Hours for about 6 Hours.

It should take (8+6+8+6+8 = 36 Hours) to reach B

How to setup this.

We are not using Fleet Management.

Thanks