US Subways Build Too Many Cross Passages

I wrote the following piece for IFP’s Transit Abundance Playbook, a collection of 15 ideas to improve transit delivery in the US.

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Other articles with overlapping topics.

Construction Physics

Reading List 08/01/26

Pepper-spray drones, China’s chip Manhattan Project, Commonwealth Fusion’s fundraise, and a proposed Dulles Airport renovation.

Brian Potter·Aug 1, 2026

Construction Physics

Why Is Everyone Trying to Build a Solid-State Battery?

A battery technology that’s getting a lot of attention is solid-state batteries, lithium-ion batteries that replace the liquid electrolyte with a solid material.

Brian Potter·Jul 30, 2026

Construction Physics

Reading List 07/25/26

China’s EV subsidies, the future of aeroderivative gas turbines, a US-Saudi nuclear deal, defective roadway guardrails, and more.

Brian Potter·Jul 25, 2026

Construction Physics

Can We Lower Construction Costs with Cheaper Labor or Materials?

Last time in our series on the nature of the construction productivity problem, we looked at economies of scale, finding that capturing economies of scale in homebuilding is difficult.

Brian Potter·Jul 23, 2026

Construction Physics

Reading List 07/18/26

A setback for California Forever, a $500 million artillery shell plant not producing any shells, the difficulty of recycling EV batteries, manufacturing wire harnesses, and more.

Brian Potter·Jul 18, 2026

Construction Physics

How Predictable Are Laws?

An enormous amount of ink has been spilled (some of it by me) on the trials and tribulations of complying with the National Environmental Policy Act, better known as NEPA.

Brian Potter·Jul 16, 2026