A pavement joint seal prevents the passage of liquids into the pavement base and the intrusion of solids into the joint. The primary mechanical requirements of a pavement seal are that it respond elastically or viscoelastically to any movement of the joint without failure and that it withstand indentation of hard objects like rocks. Because pavement joint movements and seal deformations can be large, elastomeric sealants are often used to form seals. Winter conditions are recognized as the most critical for a seal because of the possibility that failure stresses will be reached as the joint opens to a maximum and the material stiffens in response to the temperature reduction. This report reviews the specific problems and requirements that cold climates create for the performance of elastomeric seals. Emphasis is placed on the material response behavior that can lead to failure of a seal. In an attempt to clarity the mechanics of sealant and seal performance associated with low-temperature pavement applications and to address the issue of low-temperature stiffening That should be a dominant factor in the selection of a sealant, this report presents background information on the formulation and mechanical properties of elastomeric seal materials and the structural behavior of field-molded joint and crack seals. (MM).