Furthermore, owning a cold milling machine allots a contractor a certain amount of extra flexibility when bidding jobs. For the contractor who is using a sub to do the milling, there is a fixed, unbending cost associated with that service. But for those with their own machine, there's a greater ability to lower a bid because they don't have to contend with as many fixed costs. The potential result of this flexibility is a leg-up on the competition during the bid process.

When utilizing a subcontractor, the prime contractor is dependent on someone else to arrive on schedule and do the job in a timely fashion.

Even with these obvious benefits, some may still see owning and operating a milling machine as a "hassle." But when it comes to production efficiency, the true "hassle" may be experienced by not owning a milling machine.

When utilizing a subcontractor, the prime contractor is dependent on someone else to arrive on schedule and do the job in a timely fashion. And because milling is nearly always the first step in the project,  the overall productivity and efficiency of the prime contractor's operation is effectively riding on the sub.

For instance, consider a mill and fill application. With such jobs, specifications require that the contractor cannot leave an open trench. Therefore, the paver must follow right behind the mill, and all the work must to be completed in that same day. Obviously, in a case like this, the subcontractor's schedule is crucial. And if the sub is late or tied up elsewhere, all the prime contractor can do is wait and imagine the time and money being wasted.