Two
Interstates and a
U.S. Highway cross the entire bridge. Approximately 100,000 vehicles cross the bridge daily, making it the second most heavily used bridge on the river, after the I-94 Dartmouth Bridge in Minneapolis, Minnesota.
I-55,
I-64 and
U.S. Route 40 (US 40) cross the Mississippi on the Poplar Street Bridge.
US 66 also
ran concurrently over this bridge until 1979, and
US 50 was routed over it before the Interstates were constructed. In addition,
I-70 crossed the river here until 2014, when it was realigned to cross the river on the
Stan Musial Veterans Memorial Bridge when it was completed. With both I-55 and I-64 routed alongside I-70 prior to its rerouting onto the new bridge, the Poplar Street Bridge was the site of just (then) two three-route concurrencies within the
Interstate Highway System, the other being that of
I-39,
I-90, and
I-94 in Wisconsin between
Portage and
Madison. The old alignment of I-70 through downtown to the west approach for the Stan Musial Veterans Memorial Bridge became an extension of
I-44. However, motorists traveling eastbound on I-44 must continue westbound on I-70 and do not have a direct connection to the Stan Musial Veterans Memorial Bridge, while motorists traveling westbound on I-70 do not have a direct connection to I-44 westbound. Such access requires using I-55/I-64 across the Poplar Street Bridge, Westbound I-70 traffic must follow I-55/I-64 before Exit 3 on the Illinois side of the river to connect to I-44 westbound on the Missouri side, while eastbound I-44 traffic must exit onto I-55/I-64 on the Missouri side to connect to I-70 eastbound the Illinois side. ==Historical areas==