Another must-read from last week’s Reuters Infrastructure Summit: Barbara Boxer, the California Democrat who will be responsible for shepherding the next transportation bill through the Senate, says she’s open to a mileage tax and to indexing the gas tax to inflation to generate new revenue.

It’s great to hear a legislator in Boxer’s position voice support for an inflation-adjusted gas tax. Someone filling up, say, a 10-gallon tank contributes the same amount in gas taxes today as in 1993, when everyone was paying $1.20 per gallon at the pump. Too bad that unmooring the gas tax from its peg seems anathema to team Obama.

It’s also unfortunate that, when it comes to the mileage tax, Boxer’s support doesn’t appear to run very deep:

The bill’s authors, though, have rejected attaching a small device to cars to measure Vehicle Miles Traveled, Boxer said.

"We’re looking at options. Are there ways for people to — an honor
system, when they register their vehicles — just say, ‘This is the
miles I had last year, this is the miles I have this year,’?" she said.

Many, including Rep. James Oberstar, the Minnesota Democrat who will
manage the transportation bill in the U.S. House of Representatives,
have suggested attaching a machine smaller than a typical cell phone to
vehicles to record mileage.

An honor system… Maybe that works for roadside fruit stands, but funding a desperately needed overhaul of America’s transportation network? I wouldn’t bank on tamper-proof odometers.