Tag Infrastructure

5 Terrible U.S. Road and Highway Designs: Lessons Learned

By Joe P Hasler | Popularmechanics.com | August 24, 2010

Whiling away the hours in roadwork-induced stoppages, you might find yourself cursing the traffic engineers and highway designers responsible for your misery. You might praise them for finally doing something about that particularly sticky wicket of an interchange. And you might wonder to yourself, “If there was a perfect highway, what would it be like?” At least that’s what we wondered. So we found some of America’s worst examples of highway design, and talked to experts in the field to find out what it takes to build good roads.

LESSON NO. 1 ||| DON’T BULLDOZE HOUSES FOR ROADS


54caadd7dc8c8_-_worst_roads_01_0810-lg.jpg

The Offenders: The Cross-Bronx Expressway, New York City; The Alaskan Way Viaduct, Seattle


To the 21st-century American, the idea of razing homes to make room for more roads may seem inconceivable, or at least dated. Our metropolises might be strangled with congestion, but you’d be hard-pressed to find a traffic engineer or highway designer who thinks more urban expressways are the solution. That wasn’t always the case.

In the immediate post-war years, massive highway projects reshaped vast sections of the urban landscape. In New York, whole neighborhoods disappeared, and more than 5000 families were forced to move when master builder Robert Moses ran the 8.3-mile Cross-Bronx Expressway, a vital link in his vision for a massive network of urban expressways, through a densely populated segment of the Bronx. In the years after 95 divided the Bronx, the neighborhoods to the south, cut off from normal street traffic flow and related commerce, quickly faded into the blighted, burned-out south Bronx of the 1960s.

Across America, similar projects floundered in the face of community protest. The so-called “highway revolts” of the 1960s and 1970s brought central urban expressway expansion to a halt. According to Steve Alpert, a highway engineer trainee with HNTB, who studied the lessons of the Cross-Bronx Expressway at MIT, “You still never see inner-city freeways being built anymore.”

What you do see, though, is cities grappling with the legacy of old urban expressways. Seattle, for example, is currently considering a proposal to replace its Alaskan Way Viaduct. Built in the 1950s, the elevated, double-decked highway runs 2.2 miles along central Seattle’s waterfront. “This has been the center of a great debate; why put a viaduct on the waterfront?” says Ron Paananen, who is the project administrator for the proposed replacement of the Viaduct.

“It’s a barrier to Seattle reaching its world-class waterfront,” Paananen says. Recognizing this, Washington’s Department of Transportation wants to tear down the Alaskan Way Viaduct and replace it with a tunnel. “That would eliminate the grid obstruction and actually reconnect cross streets,” Paananen says.

 

LESSON NO. 2 ||| IF YOU BUILD IT, THEY WILL COME: SO PLAN FOR THAT


54caadd834f9c_-_worst_roads_02a_0810-lg.jpg

The Offenders: Interstate 25, The Valley Highway, Denver


Originally built between 1944 and 1948, the Valley Highway in Denver is one of the older segments of the Interstate Highway system. Freeways, though, tend not to age gracefully, and this particular stretch is no exception. When it was built Denver’s population hovered around 600,000. Since then, it’s quadrupled to 2.4 million. Now, 200,000 vehicles use the Valley Highway each day, and according to Steve Hersey, a traffic engineer with the Colorado Department of Transportation, certain sections of the road are “almost always backed up.” One major contributor to the congestion is the spacing, or lack thereof, between I-25’s interchanges.

“When you look at these older roads, typically what happens is you start out and you have decent spacing,” Hersey says. “But as roadside areas develop, which they tend do when you build a freeway past them, and you start adding interchanges, that’s when you get into trouble.”

While many of the interchanges on the Valley Highway are ¾ or just ½ mile apart, standards of highway design typically call for a mile between interchanges. Anything less than one mile makes it difficult to effectively place signage and adequately warn drivers of upcoming exits. Drivers also have less time to react. All of this contributes to increased amounts of weaving and merging.

 

LESSON NO. 3 ||| CONSIDER THE EARTH YOU BUILD ON: GEOLOGY MATTERS


54caadd8a556a_-_worst_roads_03_0810-lg.jpg

The Offenders: Interstate 10, Louisiana; The Alaskan Way Viaduct, Seattle


Every year, Overdrive magazine, a trade publication for long-haul truckers, polls its readers to determine the state with the worst roads in the country. For a number of reasons, Louisiana is a fixture at the top of the list. As one driver told the magazine in 2008, Interstate 10, which runs east-west across the entire state, is “rougher than a corncob.” The truckers aren’t the only ones who have noticed.

“You know you’re here from the bumps,” says Richard Levinson, a travelling jazz musician who works out of New Orleans in the winter. “As soon as you hit Louisiana, even if it’s dark and you can’t see the signs, you can tell.”

One explanation for the rough and rumbling roads of Louisiana is the soft turf on which they are built. Speaking to Overdrive in 2008, Mark Lambert, then communications director for the Louisiana DOT, said “Over time, you get waves in the concrete as the loose soil shifts or sinks, and if you’re in a long wheelbase vehicle, that gets pretty bumpy. You’ll get a bump about every 50 feet.”

In Seattle, the issue isn’t soggy soil, but shifting plates. One major factor driving the efforts to replace the Alaskan Way Viaduct is that the stacked highway is no way engineered to withstand the magnitude of earthquake Seattle, smack-dab in the middle of the Cascadia Subduction Zone, is susceptible to experiencing. In fact, the current viaduct is built in the same style as the Cyprus Viaduct in San Francisco, which famously failed in the 1989 Lomo Prieta earthquake.

“Over the past few decades I think there’s been a dramatic increase in understanding these issues, and advancement in the building codes to address them.”

 

LESSON NO. 4 ||| EVEN THE LONELIEST HIGHWAYS NEED A LITTLE LOVE (AND AMENITIES)


54caadd93106d_-_worst_roads_04_0810-lg.jpg

The Offenders: Utah Route 95, The Bicentennial Highway


Of course, linking major cities isn’t the only role of the American highway. They also provide access to the remotest spots in the country. And it doesn’t get much more remote than Utah State Route 95, otherwise known as the Bicentennial Highway. Stretching 165 miles across the high red desert between Hanksville and Blanding, the Bicentennial Highway offers a unique lesson—even roads in the middle of nowhere require attention and amenities.

End to end, Route 95 can take four hours to drive, and there’s very little in between. Along the way there are no rest areas or commercial facilities. There’s no place to buy gas, get food or stop for repairs. The pit toilets at Natural Bridges National Monument represent one of the few signs of civilization.

Kevin Kitchen, a liaison with the Utah Department of Transportation who specializes in the state’s southeastern transportation issues, says the major concern with the Bicentennial Highway is how its relatively low rate traffic volume affects road conditions. As a main access road for Lake Powell and several national recreation areas, including Natural Bridges, traffic is mostly seasonal. Those who do drive it, Kitchen says, know what they’ve bargained for. “Many motorists traveling through this area of the state comment that they choose this route precisely because of the isolation and the ability to escape roadside amenities,” he says.

But while drivers may be able to abide pit toilets and no service stations, unusable roads are another matter, and one that Utah DOT treats with extreme vigilance.

“Most of our current design efforts focus on preserving the pavement due to the typically low traffic volume,” he says. “The remote location and high desert altitude can pose maintenance and construction challenges, primarily because of the cost of mobilization.”

 

LESSON NO. 5 ||| NEVER UNDERESTIMATE THE VALUE OF A SHOULDER


54caadd96af9e_-_worst_roads_05_0810-lg.jpg

The Offenders: The Pulaski Skyway, Newark to Jersey City, New Jersey; The Valley Highway; The Cross-Bronx Expressway


Built between 1930 and 1932, and linking Manhattan, by way of the newly constructed Holland Tunnel, to the transcontinental Lincoln Highway, the 3-mile-long Pulaski Skyway was effectively the final section of America’s first superhighway. Unfortunately, it stands today as one of the earliest lessons of how not to build a highway.

For one thing, its design was inspired by steel truss deck rail bridges of the era, and was based on the railway design principles of Arthur Mellon Wellington, whose book, The Economic Theory of the Location of Railways, was first published in 1887. A central railway principle was keeping land-acquisition costs down by employing the narrowest possible right-of-way. Applied to the Pulaski Skyway, the result is inadequately narrow roadways. Its two 24-foot-wide road decks allow for just two 12-foot lanes of traffic—the minimum width allowed for highway lanes—leaving no space for a shoulder, and very little margin of error for the modern driver.

“The value of the shoulder was not fully understood in the early days of highway design,” says Steve Hersey, a Colorado DOT traffic designer. Now, road planners ideally look to have at least ten feet of shoulder on the side of a highway. One element of this is to give drivers a breakdown lane. But Hersey says that as the width of a shoulder shrinks it also affects how people drive.

“The issue is capacity,” Hersey says. “If you have a shoulder that’s smaller than 6 feet wide, and you’ve got a guard rail or barrier wall, that will impact operation. Drivers become nervous. They overreact and slow down. They weave. And all of these behaviors affect the capacity of the road.”

http://www.popularmechanics.com/technology/infrastructure/a6420/5-terrible-us-road-and-highway-designs/

©2017 Hearst Communications, Inc.

 

What Went Wrong: Investigating Russia’s Biggest Dam Explosion

By Joe P. Hasler | Popular Mechanics | February 2010 |

August 2009: a major failure occurred at the Sayano-Shushenskaya hydroelectric dam in Russia. 75 people were killed, many were injured and 40 tons of oil were spilled in the Yenisei river. With nearly 100 gigawatts of installed electric dams in the United States, experts wonder, could it happen here? PM investigates.


54ca9c46c745e_-_russia-2b-470-0210-74075297.jpg
Rescue workers clear debris and search for victims near the wreckage of Sayano-Shushenskaya hydroelectric dam’s Turbine 2. The 1500-ton piece of equipment exploded out of its seating and flew 50 feet in the air on Aug. 17, 2009; 75 people died in the accident.

Just before 8 am on Aug. 17, 2009, workers on the morning shift stepped off a clattering Soviet-era tram and made their way past security and into position at the Sayano-Shushenskaya hydroelectric power plant in south-central Siberia. In the 950-foot-long turbine hall, custodians mopped the stone floors and supervisors handed out assignments. On the roof, a technician began installing a new ventilation system. Above him soared a concave dam 80 stories high and more than half a mile wide at the crest. When operating at full capacity, the plant’s 10 interior penstocks funneled water from the reservoir behind the concrete barrier to the hall below him, where it tore past the blades of 10 turbines, spinning them with tremendous force before being flushed out of the hydro plant and down the Yenisei River.

54ca9c4667856_-_russia-map-470-0210-83690013.jpg

Completed in 1978, the Soviet-era hydro station is Russia’s largest, with enough output to power a city of 3.8 million. It was undergoing extensive repairs and upgrades that morning, so more workers were in the hall than usual: 52 on the main floor and another 63 down in the bowels of the plant. Nine of the 10 turbines were operating at full capacity–including the troublesome Turbine 2, which had been offline but was pressed back into service the previous night when electricity production dropped because of a fire at the Bratsk power station, 500 miles to the northeast. A few minutes into his shift, the technician felt the roof begin to vibrate. The vibrations grew louder and gradually turned into a thunderous roar. Alarmed, he scrambled off the roof.

At 8:13 am, two massive explosions rocked the hall. Security guard Aleksandr Kataytsev told English-language news station RT that he was one level below the turbine hall when he heard “a loud thump, then another one, like an explosion, and then the room went pitch-black.”

Turbine 2–a 1500-ton piece of machinery topped by a power generator–blasted through the floor and shot 50 feet into the air before crashing back down. The penstock water that had been spinning the turbine geysered out of the now-vacant shaft at a rate of 67,600 gallons per second. Like a massive industrial waterjet, it tore down the metal joists over Turbines 1, 2 and 3; the roof there crumpled like aluminum foil and collapsed in a tangle of glass and metal.

Water continued to pour into the hall, flooding its lower levels and eventually submerging other turbines. The plant’s automatic safety system should have shut down the turbines and closed the intake gates on the penstocks at the top of the dam, but Turbines 7 and 9 still operated at full speed, in excess of 142 rpm, triggering the crackling short circuits that darkened the plant. Amateur video footage taken downstream at the time of the accident shows bright flashes and a huge explosion in the vicinity of Turbines 7 and 9 as a wall of water spews from the structural breach near Turbine 2.

As the water level rose, employees stampeded toward the main entrance. Fearing a total collapse of the dam, many phoned relatives downstream and urged them to seek shelter in the surrounding Sayan Mountains. Among the fleeing workers were several supervisors in charge of safety and emergencies, which added to the confusion. On the fourth floor, shell-shocked midlevel operators telephoned up the chain of command for a contingency plan. No one answered.

Using his mobile phone as a flashlight, security guard Kataytsev found his way to an exit and made for higher ground. At the crest of the dam, he and several other employees struggled to manually close the penstock intake gates. By 9:30 am they had sealed all the gates, and the destruction below ceased.

In the wake of the accident, rescue crews mobilized to search for survivors. RusHydro, the partially state-owned utility company that operates Sayano-Shushenskaya, assembled 400 employees to pump out the flooded turbine hall and pick through the twisted debris. Russian president Dmitry Medvedev dispatched Sergei Shoigu, his emergencies minister, and Sergei Shmatko, the energy minister, to oversee rescue efforts. Environmental clean-up crews attempted to contain the oil spill that stretched 50 miles down the Yenisei River and killed 400 tons of fish at trout farms. Over two weeks, 2000 rescuers removed 177,000 cubic feet of debris, pumped 73 million gallons of water and pulled 14 survivors from the wreckage. But 75 workers–those trapped in the turbine hall and in the flooded rooms below–weren’t so lucky.

For Russians, the catastrophe called to mind the 1986 disaster at the Chernobyl Nuclear Power Plant in Ukraine, which was then part of the Soviet Union. Speaking on a Moscow radio station, Shoigu called the hydro dam accident “the biggest man-made emergency situation [in] the past 25 years–for its scale of destruction, for the scale of losses it entails for our energy industry and our economy.” Some commentators have called the events at Sayano-Shushenskaya the “Russian Chernobyl.” And just as Chernobyl raised questions globally about nuclear safety, Sayano-Shushenskaya has made other nations wonder: Are other hydropower plants at risk?


54ca9c4697afd_-_russia-2a-470-0210-82398737.jpg
Before: The turbine hall housed 10 640-megawatt turbines. Normally, 12 people manned the hall, but because of repair work, 115 people were on site on the day of the accident.

THE INVESTIGATION

Immediately after the accident, Russia’s Federal Service for Ecological, Technological, and Nuclear Supervision (Rostekhnadzor) launched an investigation. The official report, released on Oct. 3, blamed poor management and technical flaws for the accident.

According to the report, repairs on Turbine 2 were conducted from January to March 2009, and a new automatic control system–meant to slow or speed up the turbine to match output to fluctuations in power demand–was installed. On March 16, the repaired turbine resumed operation. But it still didn’t work right: The amplitude of the machine’s vibrations increased to an unsafe level between April and July. The unit was taken offline until Aug. 16, when the Bratsk fire forced managers at Sayano-Shushenskaya to push the turbine into service.

Back in operation, Turbine 2 vibrated at four times the maximum limit. As the control system decreased the turbine’s output on the morning of Aug. 17, the vibrations increased. The unit acted like the engine of an automobile being downshifted on a hill, shuddering violently and stressing the fatigued metal pins holding it in place. LMZ, the St. Petersburg metalworks that manufactured the plant’s turbines, gave the units a 30-year service life. Turbine 2’s age on Aug. 17 was 29 years, 10 months. Investigators determined that the power failure after the initial explosion had knocked out the safety system that should have shut down the plant–and a malfunction turned into a catastrophe.

Officials from RusHydro and the government have called for more stringent oversight of hydropower plants, but economic pressures may still put financial considerations ahead of safety. Six days before rescue efforts were halted on Aug. 29, repairs at Sayano-Shushenskaya were already underway. Rebuilding will take five years and cost approximately $1.3 billion–but a pair of nearby aluminum smelters, property of global aluminum giant RusAl, can’t wait that long. They consumed 70 percent of the station’s output and need replacement power to maintain production. RusAl and RusHydro are pressing the government for additional financing to accelerate completion of a joint venture at Boguchansk on the Angara River, now in its 29th year of construction.


54ca9c46c745e_-_russia-2b-470-0210-74075297.jpg
After: In the wake of the accident, 2000 rescuers removed debris, pumped water out of the flooded turbine hall and searched for survivors.

COULD IT HAPPEN HERE?

The U.S. has an installed capacity of nearly 100 gigawatts and an annual production of 250 terawatt-hours, which make it the world’s fourth largest hydroelectric producer. Yet even with a water-power history dating back to the 19th century, and more than 2000 such plants in operation, the U.S. has never had an event to match Sayano-Shushenskaya.

Experts agree that a similar accident is unlikely to occur here because American equipment is held to more stringent performance standards and rigid inspection regimes. The Bureau of Reclamation manages 58 hydropower plants, which produce 44 billion kilowatt-hours per year. Dan Drake, chief of the Hydraulic Equipment Group, the unit responsible for upkeep at iconic Western dams like Hoover, says bureau turbines are taken offline at the first sign of abnormal performance, and redundant automatic systems are in place. “If a unit were experiencing violent or abnormal vibrations,” Drake says, “it would shut down, and the gate at the top of the penstock would close.” Regular equipment repairs and replacement also keep dams safe.

Russia’s immediate solution to its power problem is to build more dams, but that won’t fix a bureaucratic culture that seems to devalue safety. “If they were running a turbine with known deficiencies, in essence, they’re putting economic concerns before human-life safety factors,” says Eric Halpin, the special assistant for dam and levee safety for the U.S. Army Corps of Engineers, America’s largest hydropower operator. “The principles we use are just the opposite. If it’s not safe, if there’s a risk of failure, all other benefits–be they economic, environmental or anything else–those all go away.”

ANATOMY OF A TURBINE FAILURE

54ca9c4700131_-_russia-3a-470-0210-98827610.jpg


The photograph above, of the Sayano-Shushenskaya hydroelectric power plant, located 2000 miles east of Moscow in Siberia, was taken after the Aug. 17, 2009, accident that destroyed a section of the 950-foot-long turbine hall (circled in white). Water from the Yenisei River flows through 620-foot-long penstocks to power 10 turbines, which generate up to 6400 megawatts. Turbine 2 had been offline until the previous night, when it was brought online to compensate for energy lost because of a fire at another plant. Here’s how the disaster unfolded.

1—Fatigued by vibration, Turbine 2’s fastening pins break at 8:13 am. Water rushing down the penstock forces the 1500-ton unit through the turbine-hall floor and 50 feet into the air.


54ca9c47313ba_-_russia-3c-470-0210-4909244.jpg


2—A geyser of water flowing at 67,600 gallons per second destroys the roof and floods the turbine hall. Power outages occur and communication systems fail.

3—The automated safety system also fails. Turbines 7 and 9 continue to operate even though they are submerged, causing short circuits, explosions and structural damage.

4—Employees close the intake gates at the top of the dam at 9:30 am, and the immediate crisis ends. In the following days, 14 people are rescued from the debris; 75 lose their lives.


54ca9c475eac2_-_russia-3cg-470-0210.jpg


http://www.popularmechanics.com/technology/infrastructure/a5346/4344681/

©2017 Hearst Communications, Inc.