hardball
n.— «And when word crackles on the radio that the lead truck has passed from another impossibly rutted, kidney-bruising dirt road onto a stretch of asphalt, they are about to hit the hardball.» —“Truckers of Iraq’s Pony Express Are Risking It All for a Paycheck” by James Glanz in Safwan, Iraq New York Times Sept. 27, 2004. (source: Double-Tongued Dictionary)
Hardball is used to refer to a modern improved road, usually with a rebar concrete foundation and a smooth asphalt surface. The term is frequently used in the American Armed Services as military-dialect and more as a colloquialism than in any technical sense. It is often useful in a context as to distinguish the surfaces from mere trails, unimproved dirt paths, or semi-improved gravel roads which may be nearby and when there is the possibility of ambiguity and confusion. “Keep your vehicles on the hardball because the enemy around here tends to place their bombs along the side of the road or on dirt paths where it’s easy to bury them under the loose soil.”