Like Yellowstone Park Tourist Traffic after Labor Day, the drop-off in construction volume is very noticeable during winter months. This is particularly true with concrete construction, which is usually curtailed sharply or discontinued altogether. However, the advantages to the contractor of uninterrupted activity during periods of cold weather are many and impressive. They will often outweigh the extra costs of winter construction. Every contractor faced with a cold weather shutdown must make a difficult and expensive decision. Laying off good workers creates the risk that they may not return when the weather improves. There are urgent reasons for retaining satisfactory workers on the payroll. On the other hand, it's hard to justify keeping a man on a make-work basis. Revenue-producing winter construction offers an answer to this difficult problem. Properly organized cold weather construction can result in easier operations and better quality. Within heated enclosures, labor will be more productive. Fresh concrete will be subjected to fewer variables, so its performance, both freshly mixed and in the hardened state, should be more predictable and more satisfactory. Movement of heavy equipment on unfinished sites is often easier after permanent freezing. On the other hand, excavation and earth moving is more difficult when the soil is frozen. Material suppliers, however, are usually less heavily burdened during cold weather and deliveries are more dependable. Owners will benefit also. They get earlier occupancy of buildings, which means increased production and, in some cases, additional rental revenue.