The Canadian province of Alberta has a provincial highway network consisting of over of roads as of 2021-2022, of which have been paved. All of Alberta's provincial highways are maintained by Alberta Transportation (AT), a department of the Government of Alberta. The network includes two distinct series of numbered highways: The 1–216 series (formerly known as primary highways), making up Alberta's core highway network—typically paved and with the highest traffic volume The 500–986 series, providing more local access, with a higher proportion of gravel surfaces History In 1926, Alberta discontinued its system of marking highways with different colours in favour of a numbering system. By 1928, the year a gravel road stretched from Edmonton to the United States border, Alberta's provincial highway network comprised . Prior to 1973, the expanding highway system comprised one-digit and two-digit highways, with some numbers having letter suffixes (e.g., Highway 1X, Highway 26A). In 1973, a second highway system emerged, using three digits starting in the 500s and referred to as secondary roads, while the existing system continued to be referred to as provincial highways. In 1974, provincial highways became known as primary highways; and in 1990, secondary roads became known as secondary highways. Secondary highways were abolished in 2000, with most becoming primary highways. The expanded primary highway system was divided into two subsets: former primary highways, which became the 1–216 series; and former secondary highways, which became the 500–986 series. In 2010, all highways became known as provincial highways, while maintaining the two numbered series. Despite this, the series are still often referred to as primary and secondary highways, respectively. 1 - 216 series Alberta's 1 to 216 series of provincial highways are Alberta's main highways. They are numbered from 1 to 100, with the exception of the ring roads around Calgary and Edmonton, which are numbered 201 and 216 respectively. The numbers applied to these highways are derived from compounding the assigned numbers of the core north–south and east–west highways that intersect with the rings roads. In Calgary, Highway 201 is derived from the north-south Highway 2 and the east-west Highway 1. In Edmonton, Highway 216 is derived from the same north-south Highway 2 and the east-west Highway 16. Within this series, all or portions of Highways 1, 2, 3, 4, 9, 15, 16, 28, 28A, 35, 43, 49, 63, 201 and 216 are designated core routes of Canada's National Highway System