The following is a list of the east–west arterial thoroughfares in the Canadian city of Toronto. The city is organized in a grid pattern dating back to the plan laid out by Augustus Jones between 1793 and 1797. Most streets are aligned in the north-south or east-west direction, based on the shoreline of Lake Ontario. In other words, major north–south roads are generally perpendicular to the Lake Ontario shoreline and major east–west roads are generally parallel to the lake's shoreline. The Toronto road system is also influenced by its topography as some roads are aligned with the old Lake Iroquois shoreline, or the deep valleys.