Graphic courtesy of Tishman

On one level of the World Trade Centers 16-acre, four-level basement, there are multiple and often competing stakeholders (each represented by a different color on the map).

Courtesy Dig This LLC

Dig This patrons can operate a Caterpillar D5 track-type bulldozer to create earthen mounds.

ENR readers kept many conversations alive this year—including and about types of innovation on major construction projects around the globe, a big iron playground in Vegas, tech trends on jobsites, trouble with BIM and viewpoints that struck more than a few nerves.

Some of the most-popular stories were usually the ones that inspired the most comments by readers, sometimes critical, sometimes praise-filled. As the industry reviews the highlights of 2011 and looks forward to a new year, ENR Editors present this round-up of some of the most-popular stories of the year on ENR.com.

Playing With 'Big Iron' in Vegas

One of most-read stories on ENR.com this year was about the "Dig This" construction theme park in Las Vegas. In his article, "Heavy-Duty Playground Opens in Las Vegas," contributing editor Tony Illia reported that "Dig This" is a construction theme park developed by New Zealand-born Ed Mumm, who stumbled upon the idea while using a rented excavator to build his home in Steamboat Springs, Colo. The $1-million theme park sits on 5 acres and sports five pieces of machinery, including a pair of Caterpillar D5 track-type bulldozers and three Caterpillar 315CL hydraulic excavators. What's not to love?

Cautionary Tales of BIM

Nadine Post's article about the risks associated with Building Information Modeling systems, "A Cautionary Digital Tale of Virtual Design and Construction," recounted a lawsuit over construction of a life-sciences building at a major university, noting that the case stands as the first known claim related to the use of building information modeling by an architect. Although the settlement details were sketchy, the story documented the downside of BIM as a risk-management tool if not deployed properly. XL Insurance, which provides professional liability insurance to licensed design professionals, warned readers: If you don't use BIM correctly, you can get into trouble.

Tablets Take Off in Construction

Tudor Van Hampton's story about iPads on jobsites, "Tablets Take Off in Construction," proved to be ENR's most-popular story in our technology section this year—with good reason. The iPad has provided a cost-effective entry point for many firms to deploy software on jobsites that drives efficiencies. As Van Hampton wrote: "The iPad is not replacing cell phones and laptops, and it is not the only tablet businesses are using. However, its simplicity and high brand awareness have made it a standard by which other tablets are judged."

Italy, the 'Boot and the Rock' and the World's Longest Suspension Bridge

This story by Peter Reina, ENR's London-based correspondent, about construction of the Messina Strait road-and-rail crossing between Italy's mainland and Sicily, garnered some of the most traffic to ENR.com in 2011. Readers responded to Reina's story about the final designs for an estimated $11.7-billion suspension bridge that, with a 3,330-meter-long main span, would break the current world-record length by 66%.The main-span length will surpass that of the current record-holder's, Japan's Akashi Kaikyo bridge by 1,309 m. The 52-m-wide deck will include two 14-m-wide box girders for roadways and a 7.5-m-wide central railroad girder.

Record-breaking Bridge Stars In Rugged Nevada Route

Another bridge story that readers read in high numbers was about Nevada's long-delayed Galena Creek Bridge, which critics have long derided as a "the bridge to nowhere." As the December 5th ENR cover story reported, the bridge has gone through over a decade of delays and setbacks, but the 1,722-ft-long, 295-ft-tall span, one of the costliest, most controversial projects in Nevada's history, is finally nearing completion.

Best of the Best Projects of 2010

January kicked off with ENR's celebration of the "Best of the Best" projects of 2010. Noted were the $226-million project for renovating the University of Michigan football stadium and innovative use of 3D models for the Children's Museum of Children's Museum of Phoenix. Readers loved the breadth of projects on display and celebrated in the piece.

CH2M Hill to Buy U.K. Designer Halcrow in $356-Million Deal

Mergers and acquisition news loomed large among global construction firms all year but this deal was among the largest, as ENR reported at the time. Colorado-based CH2M Hill Cos., said Sept. 26 that it would acquire London-based global transportation engineer Halcrow Group Ltd. for about $192 million in cash. The deal, which includes debt and other liabilities, could be valued at more than $356 million. Before the deal, CH2M Hill was ranked by ENR as the industry's fifth largest global design firm. Halcrow also ranked 52nd on ENR's list of the Top 150 Global Design Firms.