The Highwayman (Part 3 of 3)

Core idea

The third part of The Highwayman introduces the concept that would haunt Moses for the rest of his career: induced demand. The Brooklyn-Battery Tunnel opened May 25, 1950, with blessings from Cardinal Spellman and a parade of limousines. Within months traffic on the tunnel exceeded projections. Within a year traffic on connecting roads (the West Side Highway, the Belt Parkway) had jumped because the new tunnel had induced new trips. Other roads — promised relief — got worse, not better. The topic is Caro's first sustained engagement with the engineering finding that more roads create more traffic.

Why it matters

The tunnel opens

Brooklyn-Battery Tunnel opened May 25, 1950, with Cardinal Spellman blessing it and a parade of city limousines. The opening was triumphal. The press editorialized about one of man's greatest achievements. The atmosphere was self-congratulatory.

Induced demand

Within months, tunnel traffic exceeded projections. Within a year, the connecting roads — West Side Highway, Belt Parkway, BQE — were more congested than before the tunnel opened, not less. The phenomenon: more road capacity induces more trips. The roads built to relieve traffic created traffic instead. The finding would be formalized by transportation economists in the 1960s; Caro is documenting one of its first observed cases.

Key takeaways

Mental model

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Practical application

Example

Modern Internet bandwidth, hospital capacity, and parking-lot expansion all show induced-demand patterns. Adding capacity invites more use; the relief is short-lived. The Moses-BBT-1950 observation is the mid-century template for a now-standard finding.

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