When roads are overly large, buildings tend to be set back an unwalkable distance from the road, and regional sprawl of homes and shops and offices is more likely.
This is also true when the City or County convert a single-left turn to a double-left turn at an intersection. This enlarged intersection forever loses its ability to create a human-scaled sense of place, or any sense of walkability. Residential or small retailers are replaced by gas stations or large offices. Not only is place-making killed by these immensely oversized intersections, but such intersections undermine efforts to retain a “small town” ambiance, and undercuts the financial health of the community, as such intersections are not able to induce levels of sales tax or property tax revenue that are high enough to pay for the on-going costs of the transportation infrastructure.
Enlarged intersections and widened roads are toxic to cities because healthy cities require agglomeration economies and slow speeds to be healthy. Enlarged intersections and widened roads undermine these needs as they powerfully produce dangerously higher speeds and dispersal of land use patterns rather than compact, walkable, slower, safer patterns.