All types of large exterior doors operate slowly, but some are faster than others. Higher speed creates less of an impediment to traffic. It also reduces the amount of heat that is lost while the door is open. If the door cannot open quickly, it is likely to be left open.If there is frequent traffic, consider installing one or more quick-acting interior doors to supplement the exterior door. See Measure 6.2.5.4 for specialized doors that open quickly.For loading docks, consider installing seals between the building and vehicles that are being loaded or unloaded. See Measure 6.2.6 for the details.