Everyone has deadlines that they have to meet in their lives, and often those deadlines can be a source of stress. Many of yours may arise from your work, and the thought that your employment status could depend on meeting them may prompt you to hurry through tasks in order to get projects submitted. Imagine if your work involved driving along Manassas' roads. Once you have envisioned this, it may be easier to understand why professional drivers (including truck drivers) may be apt to speed.
If you have been involved in a truck accident in which you know the trucker was speeding, it may be easy to say that they were simply being negligent and had no regard for your safety (nor that of the others on the road). Yet (while not excusing their actions) if it were revealed that they were hurrying in order to fulfill a route on time, your stance may soften. It may be reasonable to expect motor carriers to want their deliveries to be made on time (given the need to keep their clients happy), and to even encourage their drivers to do what they can to ensure that happens. It is when the expectation is set that drivers need to exceed speed limits in order to meet delivery times that a motor carrier invites liability.
Indeed, Section 392.6 of the Code of Federal Regulations states that motor carriers cannot impose delivery expectations that do not take into account the posted speed limits of the areas its drivers will be traveling through. Doing so shows a blatant disregard for public safety, and could potentially shift liability in your accident from the trucker to their employer if you can prove that to be the case.