Hi,
It looks like you are trying to assign about 700 orders to each route. When the number of orders assigned to a route is significant large, the solver will run slow due to the large optimization search space. If you can limit the size of orders per route to 100, you should see big performance improvement.
The best way to solve your problem is to create multiple copies of each route so each route represents the workload of a day or a week, i.e. Route1-Day1, Route2-Day1, Route3-Day1, Route4-Day1, Route1-Day2, Route2-Day2,... Route4-DayN. The solution will be much easier for you to interpret and use.
Thanks.
Anna