Lake Shore Drive, a part of U.S. Highway 41 that runs parallel with and along the shoreline of Lake Michigan in Chicago, was closed to northbound traffic from the morning of Feb. 11 to the afternoon of Feb. 12 due to cracks in structural steel support girders on the elevated roadway leading up to the Outer Drive Bridge that crosses the Chicago River near the mouth of Lake Michigan. The popular thoroughfare handles 120,000 vehicles a day, half of which use the northbound lanes.
总承包商F.H. Paschen的船员，钢铁馆大都会钢铁以及芝加哥运输管理局熨斗人员完成了两个12小时的班次，以安装四个钢制结构支撑塔，在一部分驱动器下观察到裂缝，在钢梁中观察到了钢筋抬高并接近外驱动桥—芝加哥河上的一座264英尺长的双层，双层式宽阔的桥梁，在那里与密歇根湖的河口相遇。芝加哥公共事务总监迈克尔·克拉菲（Michael Claffey）表示，裂缝是由CDOT船员在2月11日上午10点左右在湖岸驱动器下部进行交通信号维修的裂缝。此后不久，市政府官员关闭了维修道路。
根据CDOT的说法，这四个新的临时塔可以为超过120万磅的压力支撑，并且在维修期间，道路升高了约六英寸，以固定由于结构梁破裂而发生的倾角。
克拉菲在一份声明中说：“我们认为这是由于腐蚀与极端温度波动的结合而引起的[2月初的温度从芝加哥的-20°摇摆到45°F]。”新利luck临时修复和帕申，CTA铁工人和CDOT正在为应在接下来的几周内完成的钢梁进行永久维修。“对于永久维修，我们将使用一对钢板，并将它们附着在现有大梁上，以重新建立和增强连接点。”
克拉菲说，CDOT已经完成了该结构的全面检查，以确定是否还有其他故障点，并且该机构将在进行永久维修工作时密切关注该结构。
The 33-year-old bridge structure was last inspected in June 2017 on its regular bi-annual schedule set by federal bridge inspection standards and it was due to be inspected again on this schedule this coming June. The 2017 inspection found that it was rated in fair condition, receiving a rating of 5.
桥条件,由伊利诺伊州运输部衡量, is determined by the lowest condition rating of the primary components of a bridge or culvert. The lowest condition rating of the deck, superstructure, substructure, or culvert. If the lowest rating is greater than or equal to 7, the bridge is classified as good; if it is less than or equal to 4, the classification is poor. Bridges rated 5 or 6 are classified as fair.
根据2018年的Association of Road and Transportation Builders Association Bridge report, of the 26,775 bridges in Illinois, 2,303, or 8.6%, are classified as structurally deficient. This means one of the primary components is in poor or worse condition.
外部驱动桥不符合联邦对新桥梁的要求，与现代桥梁设计相比，联邦公路管理局认为它“在功能上是过时的”。
"[This is an example] of what happens when Springfield and Washington legislators utterly fail to address Illinois’ infrastructure needs,” said Illinois Road and Transportation Builders Association President and CEO Mike Sturino. “The time to act is now.”
IDOT Saw all of its projects在2017年关闭由于伊利诺伊州众议院议长迈克尔·麦迪根（D）和前州长布鲁斯·劳纳（Bruce Rauner）（R）之间的斯普林菲尔德（Springfield）预算僵局。
Lake Shore Drive has seen no major modifications since its s-curve was removed in a $78-million, four-phase project that began in 1982 and was completed in 1986 [ENR Oct. 25, 1984]. The s-curve was replaced by the Outer Drive Bridge's modern southern approach which is the roadway-to-bridge structure with the girders that cracked last week.
Engineer Alfred Benesch & Co. designed the renovation of the then-48-year-old Outer Drive Bridge which created space for the eight 12-ft lanes of both the bridge and Lake Shore Drive's upper roadway and created a then-new six-lane lower roadway and the combination of bike paths and sidewalks that Chicagoans use to access Navy Pier, Lake Point Tower and Oak Street Beach. Benesch began design work on the bridge in 1975 and Paschen began construction of the project in 1982 which was completed in 1986. All that remains of the old s-curve is a part of the modern Wacker Drive. With the exception of new northbound lanes further south near Soldier Field that were installed in 1996, Lake Shore Drive has seen no updates other than routine maintenance since.
