Shortly after the morning surge of commuters had gone, the traffic moved along at 65-75 mph in complete calm, quiet, and ease. As the mild May sunlight shone just north of the eastbound in the photo, the many elements and types of expertise brought together to make the system run came into mind, one by one. The process seldom starts from scratch, since there are existing population centers to connect and probably some sort of roadway is in place. So then the expansion into a limited-access (on ramp, off ramp) multi-lane, single direction highway designed for sustained heavy traffic in all weather and built from the experience in minimizing risks of collision, or in the event of accident, the minimizing the destruction that may follow; for example by separating the opposing directions of traffic by wide medians with good visibility and restrictions on crossing over. Once a route is chosen, then widening the path requires (compulsory) property purchase and preparing the construction side by clearing all structures and vegetation. Decisions about the road bed have been researched, raw materials need to be sourced according to quality, distance, and contractor's bid price. Accounting and accountability for quality samples need inspectors and lab workers, too. Stone of various dimension, possibly recycled (old road surfaces crushed; glass, rubber) materials, steel reinforcing rods, teams of road graders, cement mixing and pouring into forms, curing, all take specifications established by experiences with other roads and with lab experiments. Blue prints encode so much knowledge, wisdom and experiences coded in visual form: angles for ramps and for road bends, rate of slope up or down, choice of paint schemes to indicate safe passing spots (for 2-way secondary roads) as well as unsafe points, signage size and verbiage least prone to ambiguity, color rules (signs for information, for commercial or cultural interest, emergency, construction ahead, electronic road conditions or traffic information. And so from concept to construction to all-weather usage by the traveling and commercial public comes together. Maintenance includes salting, plowing, recovery of wrecks, repair of minor road surface damage as well as period bridge replacement, repainting, and mowing during the growing season.
The there is the driver education, monitoring/enforcement of traffic safety codes, licensing and fees, sales and repair and routine maintenance of vehicles for business, emergency health or public safety or road service, private use, or recreation. There is car insurance (or its absence of one's coverage). All together so many things come together to make the modern wonder of personal transportation in all weather.