Today, Global Navigation Satellite Systems (GNSS) are used to provide position information as a driver navigational aid. This provides an attractive solution, as it offers global positioning using relatively lowcost hardware with lightweight computational load. In recent years, accuracy and robustness have increased, thanks to the availability of substantially more GNSS satellites, multiple civil frequencies such as L5, multi-frequency capable mass market receivers, and continental-scale coverage of corrections services like networked Real-Time Kinematic (RTK), Precise Point Positioning (PPP), and other model based approaches such as PPP-RTK [2]. One of the challenges facing adoption of RTK and other precision GNSS solutions in next-generation automotive systems is understanding the environment that vehicles will be operating in, as this could potentially be used as a core component of a safety critical system. General Motor's (GM) Super Cruise is an example use of GNSS as a core input to the feature activation criteria, only allowing the feature to be active on divided highways [3]. In order to address the integrity of such a system, the GNSS conditions on roads in terms of service denials must be understood. Some of the factors that affect the performance of GNSS and RTK use on highways include obstructions (e.g.

There is a growing need for vehicle positioning information to support Advanced Driver Assistance Systems (ADAS), Connectivity (V2X), and Automated Driving (AD) features. These range from a need for road determination (<5 meters), lane determination (<1.5 meters), and determining where the vehicle is within the lane (<0.3 meters). This work examines the performance of Global Navigation Satellite Systems (GNSS) on 30,000 km of North American highways to better understand the automotive positioning needs it meets today and what might be possible in the near future with wide area GNSS correction services and multi-frequency receivers. This includes data from a representative automotive production GNSS used primarily for turn-by-turn navigation as well as an Inertial Navigation System which couples two survey grade GNSS receivers with a tactical grade Inertial Measurement Unit (IMU) to act as ground truth. The latter utilized networked Real-Time Kinematic (RTK) GNSS corrections delivered over a cellular modem in real-time. We assess on-road GNSS accuracy, availability, and continuity. Availability and continuity are broken down in terms of satellite visibility, satellite geometry, position type (RTK fixed, RTK float, or standard positioning), and RTK correction latency over the network. Results show that current automotive solutions are best suited to meet road determination requirements at 98% availability but are less suitable for lane determination at 57%. Multi-frequency receivers with RTK corrections were found more capable with road determination at 99.5%, lane determination at 98%, and highway-level lane departure protection at 91%.