I-74 runs north-south in Iowa despite being marked as an east-west route.
Before 2004, the exit signs along I-80 (at exit #298) listed Peoria
as the destination for I-74, with Bettendorf and Moline as secondary
destinations. Never mind that, if heading eastbound, I-80 and I-74 meet
again in Illinois -- and you can keep driving straight if you're
actually heading toward Peoria and points to the east. The segment
through Iowa is more suitable for local traffic. In 2004 the signs
at the interchange were changed so that through traffic is directed
to eastbound I-80 instead of I-74.
Confused? Well, Illinois tried to remedy this problem around 1991 by
proposing a re-routing of I-74 through the Quad Cities. I-74 would have
follow the current I-80 from the cloverleaf junction in Colona (known as
the "Big X") to the exit with I-280 in Davenport. I-80 would
have replaced the current I-280, and the present I-74 would have become
I-174. Iowa leaders, concerned that some of the businesses along the present
I-80 would lose money if I-80 was re-routed, balked at the idea. In July
of 1993, the Federal Highway Administration intervened and rejected Illinois'
proposed Interstate renumbering.
page has more information on the renumbering controversy.
The Iowa-Illinois Memorial Bridge (now known by locals as simply the
"I-74 bridge") actually predates I-74 itself; it was first built
as a single span for US 6 in 1935, while the second span dates back from
1959. Tolls were collected here until 1970, and I-74 was connected onto
this bridge (which does not meet modern Interstate standards due to its
lack of shoulders and 50-mph speed limit) in 1974. Plans to improve the
corridor are online at the I-74 Iowa-Illinois Corridor page. Grading and paving for the reconstructed I-74 began in the 2015 fiscal year, while construction of the new bridge began on June 26, 2017, and is scheduled for completion in 2021.