Traditional paper and phone travel surveys are expensive, time consuming, and have problems of missing trips, illogical trip sequences, and imprecise travel time. GPS-based travel surveys can avoid many of these problems and are becoming increasingly popular in major cities worldwide. However, there is GPS signal loss or degradation in high-density cities such as NYC where urban canyon effects are significant, underground subway and commuter rail travels are extensive, GPS cold/warm start problems are obvious, and mixed land use is common. MORE about Incorporating Mobile Technology into the GPS/Web-GIS Method for Travel Survey and Research