As we look back at 2013, here's the final installment of our annual look at the top news stories of the year. Our list was compiled on the basis of popularity on our website, Truckinginfo.com, as well as our editors' opinions on which stories have the most impact on the trucking industry.

3. The Intense Interest and Increased Adoption of Natural Gas

More and more fleets bought natural gas trucks in 2013 as the Cummins ISX G became available. UPS announced it was ordering 700 Class 8 vehicles powered by LNG. Dual-fuel aftermarket systems are letting fleets enjoy some of the benefits of natural gas at a lower up-front cost, with the ability to switch to diesel if you can't find a fueling station. Companies are improving natural gas tank systems to improve range and lower weight and cost. And every week, it seems, more natural gas fueling stations were opening across the country.

2. Pilot Flying J Accused of Cheating Customers Out of Fuel Rebates

In April, the FBI, IRS raided Pilot Flying J Headquarters, looking for evidence to support allegations that the truckstop chain had cheated customers out of fuel rebates.

It didn't take long for trucking companies to start filing lawsuits. Many of those lawsuits were later settled, but a number are still pending.

By late May, two Pilot Flying J Employees had pleaded guilty.

1. The New Hours of Service Rules

Washington Editor Oliver Patton and other HDT staff stayed on top of all the twists and turns as lawsuits and appeals to Congress tried to get the DOT to back off its controversial 34-hour restart provisions in the new hours of service rules, which went into effect July 1.

Some of the most popular Truckinginfo.com stories:

8/2/2013 -- Court Upholds 34-Hour Restart, Rejects 30-Minute Break for Short-Haul Drivers

8/7/2013 -- FMCSA Stops Enforcing Break Requirement on Short-Haul Drivers

10/31/2013 -- House Bill Would Suspend 34-Hour Restart Pending Review

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