Modern asphalt is produced through the refining of petroleum but did use natural tar earlier in history but that is far more expensive.
When you are getting asphalt as a byproduct of diesel and gasoline production you may as well use it and it becomes affordable.
Concrete was used in some earlier areas if they had access to lime and brick was used in other. In Seattle boardwalks were put in for people walking and horses and wagons just dealt with the mud until the gold rush in the Yukon brought money in so there were lots of choices.
The Romans proved that chipped stone in the right configuration worked too and some of the most harsh conditions we have for roads like the Dempster Hwy use this method. Car suspension causes wash-boarding over time due to the effects of bouncing suspension not because the road bed is sinking.
If you can find the right speed a wash-boarded road is fine for 60mph which is faster than most steam trains were going at this period. You just have to find the speed where your suspension rebound lands your tire on the top of the next hump.
The words “and Defense” were added to the name of the “National System of Interstate Highways” in conference committee, almost as an afterthought, and played no role in congressional voting. See Congressional Record 102, Part 8, pp. 10991-10997. The definitive source on this history is Rose, Mark H. Interstate: Express Highway Politics, 1939-1989. Throughout the years of congressional debate, military strategists repeatedly testified that they didn’t need any particular routes or geometric specifications, always saying that highways built to promote commerce would also serve their needs. To Pres. Eisenhower, the public-works and job-creation aspects of the system were about as important as defense aspects. I am not aware of any serious civil defense or military rationale that was part of Congressional debate.
As for the original query, the majority of U.S. Highways were paved by 1940, but not the entire network. Some state highway networks still had unpaved sections into the 1980s (Oklahoma comes to mind, and perhaps New Mexico.) As noted, many many county roads and exurban streets are still unpaved.
Looking at all roads and streets, FHWA statistics show rough 25% were surfaced by 1930, about half were surfaced by 1945, and roughly 75% by 1975. Perhaps FHWA counts differently now, because the most recent table shows one-third of all roads and streets are unpaved, including perhaps 300 miles of “state highways.” (Things are complicated by states like Virginia, where all public roads are on the state highway system.)
The Dalton Highway in Alaska is 414 miles long and only 109 miles are sealed so that would account for those 300 miles of “state highways” right there.
Sydney and later Melbourne used wooden cobbles for roads extensively.
Most of Melbourne’s CBD and inner suburbs were paved with wood(red gum) blocks from the 1880s. A.C. Mountain, (city surveyor of Sydney (1879-1886) and Melbourne (from 1887) recorded 112 acres (45 ha) of wood paving in Melbourne’s streets to Sydney’s 103 acres (41 ha).
The blocks were progressively replaced with concrete from the 1930s, there was 149 acres (60 ha) still in use in 1960s and some remnant sections are still there.
Echuca, a town in northern Victoria was used as a test site in the 1860s and some are still doing their job around the old river wharf area 150 years later.
I always wonder about this, because in L.A.–where it doesn’t even rain that much, and there’s no snow–there are some concrete streets, but most are asphalt. It seems, however, that asphalt has to be repaved very frequently, and concrete does not. So is it really that much cheaper when this is taken into consideration?
Right. I’m not sure why this should be surprising. Even in cities you can find an occasional street that is unpaved. Maybe it’s only a few blocks, but this happens.
Remnant sections? Where? I’m sad that I wasn’t able to do anything to preserve the last sections I knew (I was disabled at the time).
Also… the Eyre Highway, the main road linking the East and West coast of Aus. 1976. In 1975 it was still an iconic road trip from Syd/Melb across the Nullarbor Plain. Then they sealed the road, and it was just another very long road. Around the top to Darwin came even later, and last I knew the road south from Alice Springs was only sealed for a few miles out.
Also note that very few of the gravel roads anywhere are properly “made” with sand as well as gravel. Although I do see made pedestrian and bicycle tracks. AFAIK, it just isn’t worth it for an unsealed road, because motor traffic destroys the surface so fast.
… And the reason I noticed the wood-block pavement in Melb. is that it is characteristically New World: Europe ran out of wood and had to turn to coal for heating, so stone and brick paving is the flip side of the industrial revolution.
I asked the family sage and she said they thought there were still some between the tram track along Elizabeth St near the Queen Vic Markets. I thought I recalled seeing them on William St near the Flagstaff Gardens.
What we in Michigan call “dirt roads” are still very common outside of fully developed areas. There’s even an adjacent sub that has two dirt roads, and that’s an inarguably fully-developed area.
We’re a PLSS state, so other than where natural barriers prevent is, these dirt roads form a mostly-regular grid crossing nearly the entirely of the lower peninsula. Given the duty use of these roads, there wouldn’t be much sense in paving them.
I only mention this because it seems from the other participants of this thread that dirt roads are quaint and unusual. In Michigan, MDOT says there are 120,000 miles of paved roads, and an old (1984) estimate indicates there are 43,000 miles of unpaved road. That’s more than a quarter of all of our roads!
True story. Back in the 70’s I was at a city council meeting where they were arguing over how much to spend on repaving a major street. One of the council members said, “What’s so great about concrete? The street’s concrete and we still have to repave it.”
Another council member shot back, “We built the street 40 years ago. THAT’S what’s so great about concrete.”
That was in 1919 and a young Lieutenant named Eisenhower took part. That experience plus his exposure to German Autobahns doubtless inspired his plans for the Interstate Highway system.
In my family, in 1939 only 20 years after the Army convoy, two of my 50-something great-aunts drove themselves from central Pennsylvania to Texas, California and Oregon.
My first experience with gravel roads was in Michigan. I went to stay with my roommate at his parents’ house one weekend, and they lived on a gravel road, though they called it a dirt road.
I’ve never seen a gravel road in the South, where I’m from. All of the roads are either paved or bare dirt (though many people have gravel driveways).
In NE Florida, near where I grew up, there is still a brick road in existence Old Brick Road. I drove the entire length of it once, and it’s slow going or else it will really do a number on your suspension.
I find that people make way too much of this historic coincidence.
As Earl Swift notes in The Big Roads, p. 157: “When Dwight Eisenhower took office in January 1953, the Interstate Highway System had officially existed for more than eight years…He entered the Oval Office professing an interest in building ‘a network of modern roads’… He didn’t know that the executive and legislative branches had already worked out the details of the network he sought.”
The other major players—Thomas MacDonald of the Bureau of Public Roads, Sen. Albert Gore, Rep. Hale Boggs, even FDR—were far more important than Ike.
Modern readers love to elide from Eisenhower’s 1919 convoy to his viewing of German autobahnen to the last-minute insertion of “and Defense Highways” into the congressional bill title to the blue signs that went up in 1991, making it a simple “great man” story. In between, of course, were the parkways of New York and Washington, the urban superhighways of Detroit and Chicago, the Pennsylvania Turnpike—and the congressional funding fights of the 1950s in which the Eisenhower Administration was notably clumsy and clueless and played no role other than signing the finished bill.
My town and several of the neighbouring towns in the built-up London commuter belt have several enclaves with unpaved residential streets. Example. Other than residential roads, though, gravel and dirt roads don’t really exist in the UK. We do have “green lanes”, which are a bit different and not really proper roads.
