What is an old alignment, as it pertains to a road or highway? Simply put, an old alignment is something that once existed that no longer has that status. If U.S. 12 used to be routed one way through town, a new road was built, and the U.S. 12 signs were moved to that...or if the signs came down and U.S. 12 was decommissioned entirely...the old route would become an old alignment.
An old alignment can go for a few feet, or go halfway across the country. It could have once been an Interstate highway, a county highway, or a turn-of-the-century auto trail, turnpike, or military road. It can still be a busy highway; it can be a frontage road or dead-end stub; it can be a residential street; it can be closed to traffic and literally crumbling into dust...but the common thread is that it used to have more significance than it does today. Sometimes, there are multiple parallel alignments of a given road snaking through the landscape.
Why are old alignments interesting? Travel by road was a far different experience 50, 75, or 100 years ago. Roads were narrower, curvier, and less often paved; major arterials routinely connected and crossed through city centers; automotive machinery was more primitive; railroads dominated over highways for purposes of freight and long-distance travel. Old alignments offer a glimpse into this past...and offer a chance to uncover a taste of the sights, experiences, and challenges that travelers went through many years ago.
How do you find old alignments?
- Old maps are the most obvious starting point. Vintage tourism and gasoline maps are helpful, but the most invaluable resources to turn to are USGS and Army topographic quadrangle maps. Most libraries have at least a few of these in their collections. Several online resources also exist: MSR Maps is one site that has USGS map imagery available, and MyTopo has historic maps for several states up to view or download. Many USGS base maps were used through subsequent revisions for decades on end, so even a newer topo map can reveal secrets about an area's infrastructure from decades past.
- Plat maps and plat books are another good resource to browse; in libraries or online. Older plat books from the nineteenth and early twentieth century often go into extensive detail in documenting the street and railroad layout of a place. Current plat maps can also reveal old alignments, since property lines often delineate the historic course of streets and roads even if the streets and roads in question no longer exist.
- Recent aerial imagery is readily available on Google Maps and other similar websites. Some historic aerial imagery is also available from Google Earth (for those able to run it) and Historic Aerials, which is really helpful in determining where things used to be.
- Suggestive road and street names. The connection to the past is obvious enough if a street or road calls itself "Old Rte. 35" or "Old CTH Q," but suggestive names go beyond that. If a street is named "Green Bay Road" or "Old Hinton Road," there's a good chance that it was part of a through highway to Green Bay or Hinton at one time. Something called "Plank Road" would quite likely have been a busy toll road surfaced with wooden planks in the 19th century during the brief time that sort of road was popular. Keep an eye out for anything with "Old," "Turnpike," or "Highway" in the name.
- Diagonal anomalies to the street grid. The earliest roads in a typical town were built atop pre-existing military roads or wagon paths that gave no conciliation towards uniformity or 90-degree-angle surveying. Sometimes, these originated as Native American Indian footpaths dating back many hundreds of years. In either case, these roads were in place for an expanse of time before street grids and residential areas wrapped around them.
- Obtuse angles. If a road splits off from a current highway at an obtuse angle and then returns to it a few feet or miles later, it becomes painfully obvious that the highway in question used to be routed that way...especially if utility poles or other artifacts continue to line the older road.
- "Historic" signage. Sometimes, an old alignment has so much cultural significance that it's still marked as such. The course of U.S. Route 66 is well-marked in the states it passes through; even though the highway in question was decommissioned in 1985. Early highways and auto trails like the Lincoln Highway and National Road are also marked by extant signs and monuments along the way.