Why Are American and Arabian Roads the Straightest?
While a winding mountain road offers a driving thrill, the world's longest, perfectly straight roads are not accidental. They are the result of specific engineering logistics and legal frameworks like the Public Land Survey System (PLSS) and desert topography. Technically, these routes represent the shortest distance between two points (A to B), but they introduce unique mechanical hazards like tyre delamination and highway hypnosis that define the driving experience in the American West and the Arabian Peninsula.
1. The Grid System: How Law Defined the Asphalt in North America
The unbending straightness of roads in the American Midwest and Canadian Prairies is a direct result of the Public Land Survey System (PLSS). Established by the Land Ordinance of 1785, this system divided land into a rigid grid of six-mile square townships. Logistically, when 20th-century engineers began laying roads like ND-46 W, it was cost-effective to follow these straight property and county borders. This legal framework ignored topography, forcing roads to run perfectly North-South or East-West regardless of minor terrain variations.
2. The Desert Factor: Engineering for Maximum Cost-Efficiency
In regions like Saudi Arabia and the Australian Outback, the lack of mountains or major river systems allows for Shortest Path Engineering. Technically, every degree of curvature adds to the total volume of asphalt, transport logistics, and labor costs. This logic produced Highway 85, which maintains 822 km (510 mi) of uninterrupted straightness. In these environments, the primary technical challenge shifts from steering to thermal management; tyres running at constant high speeds on 60°C asphalt suffer from localized heat buildup, increasing the risk of sudden delamination.
3. Mechanical and Psychological Hazards of Straight Driving
While mountain passes like the Col du Galibier demand physical handling, straight roads demand psychological endurance. Technically, the lack of steering input leads to "Highway Hypnosis," a trance-like state where the brain stops processing visual data. Logistically, some straight roads in Australia now include intentional "fatigue bends" to force driver engagement. Furthermore, engines running at a constant RPM for hundreds of miles require perfect cooling systems; any minor coolant leak becomes a catastrophic failure when there is no variation in engine load for hours.
