Condition of drivers also may deteriorate during the night with fatigue and perhaps chemical impairment. Projects near neighborhoods require limited working hours so as not to disturb residents. The final factor is cost. Cost must be weighed against the benefits and hazards of night work. In most cases night work almost doubles the cost of a project.
Road construction is frustrating.
Timing of construction projects depends a great deal on the availability of funds and time of year. Major projects are expensive, and it is often not possible to fund them entirely in one year. A good example is the North Outerbelt Widening and Spring-Sandusky Interchange projects. The long term nature of these projects allow payments to be spread out over several years. Maintaining traffic is also a concern.