Traffic on the National Highway System has dropped to its lowest level since the late 1980s, according to a new study.

The National Center for Transportation Statistics (NCTS) report, released Wednesday, showed that the average speed of the National Highways Network (HAN) network has dropped by nearly a half-million miles per hour since 2000, the first year it was implemented.

In contrast, traffic on the state highway networks fell by more than 1 million miles per day.

The average speed on the HAN network fell by nearly 4 million miles in that same time period, the report found.

The network has seen more than 11 million miles of new capacity installed in the last two years, the most in more than 30 years.

But the NCTS report found that only 6.2 percent of the network is now operational, down from 8.4 percent in 2014.

The report also said that the network could be expected to see more congestion over the next decade.

The state of Texas was the worst offender with a rate of 0.8 percent congestion, according the study.

New York was third with a 0.4 rate, and New Jersey was fourth with a 1.1 rate.

Meanwhile, the U-M Transportation Institute said that its network experienced the biggest growth in the network in the first three months of 2017.

The study found that more than 8.6 million miles were added to the network between October and December of 2017, which was nearly double the 6.3 million miles added between October 2017 and January 2018.

The NCTS study found a sharp drop in congestion for the first few months of 2018, though traffic on most routes was still higher than in the previous year.

The data show that the first half of 2018 saw a slight increase in congestion, the study said.

It’s unclear what caused the slow start to the year.

While congestion is typically bad news for an economy, congestion can also be a boon for people, especially during the holidays.

The congestion data also show that, in some places, traffic has been picking up during the holiday season.

In some cases, traffic is going from negative to positive, or from zero to 10.

For example, in the western U.K., traffic increased by more in the third quarter of 2018 than in any other quarter.

But congestion was still low for the second quarter, and that may not be a good sign for a U.N. summit on climate change later this month.