To push the trail metaphor further, every summer I visit a particular national park. One of my favorite trails there was the main route through the forest, which also served as a secondary path for rangers transporting equipment by car. At several points, the trail crossed rivers, and the bridges always seemed overengineered, with unusually high weight limits. Especially since the rest of the trail was barely passable by vehicle.

A few years later, the park began offering cottages along the route and started paving critical sections, particularly steep areas where trucks (presumably transporting building materials for the cottages) struggled. Had those bridges not already been built to support these trucks, the park would have needed to close the trail for upgrades. Or make a second trail with the new requirements in mind.

The trail expanded faster than it was paved, but each year you could go further as the trail grew longer, and faster as key sections were improved.