The Toledo Terminal Railroad was completed in 1903. At one time, owned by most of the major railroad companies that passed through Toledo, it essentially formed a "loop" around the city, connecting the various industries to the railroads. It crossed the Maumee River in two places; the Upper Bridge and the Lower Bridge. In its heyday, the railroad was double-tracked all the way around the city of Toledo, except for the Upper Bridge.
Over the years, railroad companies merged, and finally, the Chesapeake and Ohio purchased the railroad in 1947, itself becoming CSX in the early 1980s. The TT formally came under CSX ownership in 1989. At the same time, local business along the track began to use trucks for transport, ending the use of "backside" of the TT (the backside is the portion of the TT along the west side of the Maumee River) for originating traffic. Around this time, the backside was also "narrowed" from a double track to a single track.
Because of Conrail, the Norfolk and Western (later Norfolk Southern) had to obtain trackage rights to use the backside of the TT, in order to access customers in Maumee and its former Wabash and Cloverleaf mainlines (abandoned south of Maumee, see Montpelier to Maumee, Liberty Center to Maumee, and Toledo, OH to Craigville, IN). N&W accessed Maumee via the Upper Bridge until May 1982, when a derailment damaged the bridge. The TT decided that it would not repair the bridge, abandoning the track from Gould (where the Wabash lines crossed the TT) to Bates (where the B&O crossed the TT) and the bridge in the process. Despite legal battles with the city of Toledo, in the end, the TT got its way. This forced trains to detour around the north of the city, utilizing the rest of the backside of the TT.
After the TT decided to abandon the Upper Bridge, it upgraded the backside to continuously welded rail. From 1982 to the early 1990s, the N&W trains often caused headaches for Toledoans as the frequent, long, and slow grain trains held up traffic at all the backside's grade crossings. After NS (formerly the N&W) abandoned its ex-Wabash lines out of Maumee in the early 1990s, this reduced traffic on the backside of the TT considerably, yet furthermore reducing the usefulness of the backside. This left the backside only for NS to access its remaining customers and yard in Maumee.
In 1998, NS and CSX split up Conrail, with NS obtaining the ex-NYC "Water Level route" as its busy Chicago Main through Toledo. The portion of the TT east of the Maumee River saw an increase in traffic, and still is very busy to this day. With the restrictions of Conrail gone, NS began to build a connection from its newly-acquired Chicago Main to the former Wabash main to access Maumee. It was completed in 2000, ending NS' use of the backside of the TT. The last train to run on the line was in July of that year. Around this time, the city of Toledo and the University of Toledo began to study the right of way's feasibility as a rail-trail.
Throughout the 2000s, the backside sat unused, with NS eventually removing the diamonds of the TT and the Chicago Main (Nasby) around 2006. Beginning in 2009, track removal crews began to tear out the track around Monroe Street. In early 2010, CSX filed for abandonment of the line, between Temperance, on the north side of Toledo, to Vulcan, where the TT and former NYC "Old Road Division" (also abandoned north of the Ohio and Michigan state line, see Ottawa Lake, MI to Riga, MI) diamond was. After permission was granted, full-fledged track removal began, with the entire backside from Temperance to the Upper Bridge torn out, minus the small, out of service segment from Gould to Nasby, and north of Nasby to Vulcan, a small amount which is still active. The portion from Medford Drive to Copeland Avenue was torn out in 1996.
The upper bridge itself is still standing, minus any decking and tracks. The Lower Bridge and the eastern portion (east of the Maumee River) of the TT are still in use by CSX. At the time of this writing in December, 2010, track removal had been completed with all crossings removed, though pole lines, ballast, and signage (mile-markers and whistle-posts) remain. The I-475 overpass is still in place, though its days are numbered as ODOT is currently widening I-475, and its removal is in the works. While the only active segment of the backside is currently from Nasby to Hill Avenue, NS is planning to reactivate the portion north of Hill Avenue to Vulcan, which was not torn up, in order to bypass and abandon the portion of the ex-Old Road Division from Vulcan to the Air Line yard along the Chicago Main. The interlocking towers at Nasby and Bates are still standing.
Thanks to Aaron M. for contributing information about this route.