Many navigation techniques have now become so reliant on GNSS that there is no back-up when there is limited or no signal reception. If there is interference, deliberate jamming or spoofing, and/or blockage and reflection of the signals by buildings, navigation could be lost or become misleading. Other navigation techniques harness different technologies such as Wi-Fi, eLoran and inertial navigation. However, each of these techniques has its own limitations, such as coverage, degradation in urban areas or solution drift. Therefore there is a need for new navigation and positioning paradigms that may be integrated with GNSS to increase the reliability of the system as a whole. This paper presents the results of a feasibility study to identify a set of novel environmental features that could be used for road navigation in the temporary absence or degradation of GNSS. By measuring these features during times of GNSS availability, a map can be produced. This map can be referred to during times of limited reception. The most feasible environmental features are identified, their potential for providing position information is quantified and various methods of combining these features are analysed. It was found across multiple test routes that it is possible to determine the position of a vehicle along a route using three sensors: barometer, magnetometer and a camera looking at road signs. This work is relevant to any road application that requires resilient positioning. Examples include navigation and tracking of ambulances, fire, police and security vehicles; high-value asset tracking; transport logistics; road-user charging and pay-as-you-drive insurance
