Take aggregates, or rock-based materials that go into gravel (as well as other compounds). Aggregates are ground and glued together at high temperatures with liquid bitumen, a byproduct of the oil refining process, to pave our trails and highways. Typically, roads are built by piling a layer of aggregates, on rocks of various sizes, shapes, weights and mineral properties that are collected at quarries, sorted and sifted through 'screeners', trucked away for remix with rocks from faraway places to meet the best specs, and topped with asphalt or concrete– and voila! You've got a new road! When oil prices nudged the stratosphere as they did last year, scientists and industry leaders raced to find ways to cut costly aggregate production and transport costs, as well as ways to address occasional aggregate shortages.