  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%.
