Weather conditions have significant impact on road safety and roadway maintenance operations. Road Weather Information Systems (RWIS) play a significant role in providing weather and surface conditions to transportation agencies to monitor weather events. Fixed installations of RWIS are used for weather and pavement surface monitoring. However, permanent fixture installations may not be feasible due to reasons such as cost, accessibility to the site, siting concerns, and terrain. Portable RWIS provide a cost-effective solution in areas where permanent weather station installation is not possible. This study discusses use and benefits of the portable RWIS and outlines the issues involved in building them. This thesis presents the system design for building prototypes of two portable RWIS systems to be used by Massachusetts Department of Transportation (MassDOT). Portable RWIS consist of weather sensors and pavement sensors installed on a trailer-based platform and operate on solar power. The RWIS equipment mounted on trailers consists of non-invasive pavement sensors, wind sensor, precipitation sensor, atmospheric pressure sensor, humidity and dew point sensor and data logger to transmit data from the sensors to a central server. RWIS equipment from two different manufacturers have been selected. The two systems have been evaluated for their cost, operability, ease- of-use and deployability. A field study of two portable RWIS has been conducted to test accuracy of the data collected by these systems and the results have been evaluated. Characterizing the issues involved in developing such portable systems provide insights into situations where these systems may be most applicable.