12 SPRING 2019 • POPSCI.COM
Limited lanes
Designers of even the broadest 20th-
century bridges didn’t plan past the
new millennium. Despite the number
of cars per person more than doubling
since the ’50s, most commuters still
rely on undersize infrastructure. When
rain, ice, low visibility, or rush hour
strike, the result is a long line.Too weak
A new four-door in 1987 weighed 3,
pounds; its 2016 equal topped 4,000.
The extra tonnage per car means many
passes can’t accommodate the autos
that modern drivers increasingly
prefer. The Brooklyn Bridge, for one,
bans vehicles more than 3 tons; that’s
lighter than many SUVs.No backups
In 1967, a single link in the chain
suspending Ohio’s Silver Bridge
snapped, bringing down the whole
span and killing 46 people in the
process. Doubling up on essentials,
such as structural supports, would
have provided crucial redundancy
and avoided a single point of failure.- Limited lanes [ 1 ]
- Too weak [ 2 ]
- Poor upkeep
- No backups [ 3 ]
THEN
CHARTED
Outdated materials •