The Automobile and the American Road Bridge – Part 1


1828 stone-arch “S bridge” and 1932 concrete-arch bridge, Blaine, Ohio

(first posted 10/6/2015)    Rivers, streams, lakes, and valleys have always hindered our ability to get from here to there. That’s why bridge building has been a fundamental human engineering activity since the dawn of civilization. We humans have always been a resourceful species that doesn’t let obstacles stand in our way! But thanks to the automobile, modern times have brought bridge building to a stupefying scope and scale. Unfortunately, it’s often been at the cost of aesthetics.

This is the first of two articles outlining the history of road bridges in the United States. Today, Part 1 details the kinds of bridges built before the automobile era. Tomorrow, Part 2 will show the rapid evolution of the bridge during the automobile era, as well as how the automobile has played a role in so many older bridges being lost to history – and how there are efforts to save some of those that remain.


Modern steel-and-concrete bridge, Shoals, Indiana

Most bridges built today are some variation on this, generally built of steel beams and supported by T-shaped piers. They’re cost effective to build and maintain — critical components of any engineering effort. Unfortunately, they also utterly lack character. From the side, they look as utilitarian as a kitchen appliance. Driving over them, except for the concrete barriers on either edge, you might not even know you are on a bridge.

That hasn’t always been the case. In times gone by, beautiful bridges have been made of wood, stone, and exposed iron and steel.


1913 stone-arch bridge, Ripley County, Indiana

Stone has been used since ancient times. Arches are naturally strong, and stones can obviously be arranged to create them. This little one-lane stone bridge on a rural road north of Madison, Indiana, is a latecomer, having been built in about 1913.


1828 stone-arch “S” bridge, Guernsey County, Ohio

Even in the stone-bridge age, engineers were constrained by cost. It is more complicated and expensive to build and maintain a bridge that crosses a stream at an angle, but roads don’t always reach the stream perfectly perpendicularly. So sometimes bridges were constructed to cross a stream squarely, with approaches built at angles to connect with the road. This created an S shape, which is why these are called S bridges. Most of those that remain are in Ohio, like this one on a former alignment of US 40 east of Old Washington. It carried traffic from its completion in 1828 until 2013, when structural worries forced its closing.  The stone bridge pictured at the top of this post is another S bridge that once carried US 40, near Blaine, Ohio.


1819 stone-arch bridge, Washington County, Maryland

The oldest remaining bridges in the United States are pretty much all made of stone. This bridge west of Hagerstown, Maryland was built in 1819. It carried US 40 until 1937. If you’re wondering why I’m showing you all of these stone bridges along US 40, it’s because from Maryland to Illinois, US 40 laid out (with a few exceptions) over the old National Road, the nation’s first federally funded road, built in the early 1800s. Those were prime stone-bridge years in the United States.


1813 stone-arch bridge, Garrett County, Maryland

An even older stone bridge carried the National Road over the Casselman River in western Maryland. It was completed in 1813. Its unusually high arch was meant to allow boats to pass under. It became part of US 40 in 1926, and even though a newer US 40 bridge was built just downriver in 1933, this bridge carried traffic until 1956. It is open only to pedestrians today.


1849-60 suspension bridge, Wheeling, West Virginia

Stone bridges can span gaps only so long, however. The Ohio River is more than 1,000 feet wide where the National Road meets it in Wheeling, West Virginia. Bigger engineering guns were required to span that a gap. And so the famous Wheeling Suspension Bridge was built, the state of the engineering art upon its 1849 completion. The challenge with the state of the art is that the kinks might not be worked out yet: the deck collapsed in 1854. It was rebuilt by 1860. This isn’t a particularly great photo of the bridge, but I’m including it because I happened to get a genuine Curbside Classic in the shot.


1860 suspension bridge, Wheeling, West Virginia

I walked out onto the deck for this shot. Cars can still drive over this bridge, but at a top speed of 50 miles per hour, and separated by a good 100 feet.


1875 Medora Covered Bridge, Jackson County, Indiana

Other types of bridges were built through the 19th century, most of them of wood or iron. Probably the best-known kind of wood bridge is the covered bridge. The cover is largely to protect the wooden trusses from the weather. You don’t want load-bearing wooden members to rot! This is the Medora Covered Bridge, near the little town of Medora in southeastern Indiana, and it sports a fresh cover. The covers, being subjected to the deteriorating effects of rain and sun, needed to be replaced from time to time.


1875 Medora Covered Bridge, Jackson County, Indiana

It’s not very often you get to see a covered bridge undressed! This is what the Medora bridge looked like after its old cover was stripped away. This bridge hasn’t carried traffic in decades; the state highway that it once carried now bypasses this old bridge on a modern steel-beam bridge.


2006 Bridgeton Covered Bridge, Parke County, Indiana

It’s also not too often you get to see brand-new wooden bridge trusses. The 1868 covered bridge in Bridgeton, Indiana, was destroyed by arson in 2005. It had been a centerpiece of the many, many covered bridges in Parke County and a feature of the annual Covered Bridge Festival, so locals immediately rebuilt it to original specifications. I’m sure this bridge could support traffic, but like the Medora bridge, it is only a popular tourist attraction today. After it opened, I went right out and got this photograph. The curved members are Burr arch trusses, a truss type common among Indiana covered bridges but unusual elsewhere.


Ca 1920 wooden bridge, Jennings County, Indiana

Some wooden bridges were not covered, like this bridge in Jennings County, Indiana. It was built about 1920 to elevate a road over a railroad track, known in the biz as a “grade separation.” 1920 was mighty late for a new wooden bridge, but railroads still sometimes built them even that late. Sadly, this bridge was demolished a few years ago when nearby US 50 was realigned.

Believe it or not, this bridge actually carried US 50 for a while after the US highway system was created in 1926. It carried Indiana State Road 4 for nine years before that. Cars created demand for highways, and states had little choice but to route highways over existing roads. Frequently, the best roads available were unpaved and featured narrow bridges.


1903 Washington Road bridge, Knox and Daviess Counties, Indiana

All of these bridges were built for the light, slow traffic of horse riders, animal-drawn wagons, and pedestrians. As cars became increasingly popular, they overwhelmed the inherited infrastructure. This 420-foot-long one-lane bridge, built in 1903, carried the first alignment of US 50 between the Indiana towns of Washington and Vincennes a quarter century later. Can you imagine encountering an oncoming car here? Nationwide, state highway departments were formed to improve roads and bridges to suit the new kinds and volumes of traffic they were getting.

But meanwhile, wood truss bridges had given way to iron and steel trusses, and were the dominant bridge type by the early 1900s. Virtually all of them featured wooden decks, however. When you see a steel deck like the one on this bridge, you can be certain that it was a later replacement. This steel deck was probably installed with a renovation of this bridge in 2006.


1891 Cooper Iron Bridge, Putnam County, Indiana

Interestingly, bridges like these can sometimes be moved to new locations. This 1891 iron bridge was built to carry the National Road near Putnamville, Indiana. (It still wears a wooden deck, but it’s certainly just the latest of several replacements.) When a wider concrete bridge was built in about 1923 to carry this road, this bridge was moved, I believe intact, about a quarter mile up the creek to span this county road.


1887 Whipple through truss bridge, Aurora, Indiana

Truss bridges come in many types. Through trusses – the kind with connecting members over your head – are the most common, and there are dozens of types of through trusses. Pony trusses (no overhead members) are probably the next most common type. There are even bridges with trusses under the deck. The many truss variants have names: Pratt, Parker, Howe, Camelback, Warren, Fink, Bowstring, Baltimore, King, Waddell, K, Pettit, Pennsylvania, and others. This 1887 bridge in the Ohio River town of Aurora in Indiana is a Whipple truss.

Part 2: the kinds of bridges built as the automobile became popular – and how that doomed so many of the bridges described in Part 1.