The French TGV network is a great example of the Phased Network Approach in action.

The Phased Network Approach combines the transformative power of high-speed lines with the geographic coverage of existing infrastructure.

High-speed trains are a lot like regular trains, with steel wheels traveling over steel rails. But on dedicated, high-speed tracks, they can go really fast. Today’s fastest trains regularly travel at 220 mph. (A French test train reached 357 mph, the current record.)

Because they use the same basic technology as conventional trains, high-speed trains can take advantage of our existing railroad network.

Just as a car journey begins on regular roads and then moves to an interstate highway, high-speed trains  travel seamlessly over both shared-use tracks and new, high-speed tracks.

That’s why, in the Phased Network Approach used by most countries, segments of high-speed line blend seamlessly with upgraded conventional tracks that accommodate slower passenger and freight trains.

So a single, high-speed segment creates faster travel to many destinations—not just two end-point cities. That multiplies the value of high-speed rail investments and leads to broad, strong political support for trains and transit.

Key Elements

Each country has taken a slightly different approach to meet its local needs, but all networks share three key elements:

A. A big-picture, long-term plan that coordinates multiple projects

B. Modern, High-Performance Trains built to the safer, and more cost effective, European safety standards.  Modern high-speed trains also take curves and accelerate faster on conventional tracks than older trains—saving riders time and frustration.

C. Three different kinds of tracks

  • High-Speed Lines transform travel with frequent trains running from 125 mph to 250 mph, depending on local conditions. They’re flat and straight, with gentle curves. There are no intersections and no crossings, since all roads and other railroads go over or under the line, and heavy freight trains run on separate tracks. The line is protected with fencing and electrified—since that’s the best, and greenest, way to power trains.
     
  • Urban Trunk Lines use existing rail corridors through cities to create electrified tracks for lightweight passenger trains—both high-speed and commuter. Heavy freight trains use separate tracks. Preferably, there are no highway crossings. Urban trunk lines maximize the value of existing infrastructure and reduce the initial cost of building a viable high-speed line.
     
  • Shared-Use Lines use upgraded existing routes to connect cities and towns. Passenger trains mix with heavy freight trains. Most commuter and Amtrak lines are shared-use lines.) Notable examples include the Capitol Corridor in California, the Lincoln Corridor in Illinois, and the Brightline/Virgin Rail line in Florida.
The French TGV
Today's TGV (High Speed Train) network serves most of the country and extends internationally. Compare this with the LGV (High Speed Line) network below.

How France created a world-class high-speed rail system—one segment at a time

Europe’s first dedicated high-speed line—the LGV Sud Est (or Southeast High Speed Line)—shows the wisdom of this approach.

The LGV Sud Est is frequently called the Paris – Lyon line. But, when the line opened in 1981, the high-speed segment was only two-thirds of the total distance—about 180 of 280 miles. TGV (or High Speed Train) trains used conventional, shared-use tracks for the first 100 miles south from Paris, and they used conventional tracks as they approached Lyon. 

This blend of high-speed and conventional tracks cut the travel time from 4 hours to 2 hours and 40 minutes.

The next high-speed segment—another 70 miles—opened in 1983 and slashed the travel time to just 2 hours. Other destinations linked by the network in the early years included Avignon, Geneva and Montpellier.

France has used this strategy for forty years. It gradually connects new cities to the network and blends segments of high-speed rail with conventional tracks. As new high-speed tracks are added, the network is built out and travel times are slashed.

This is the LGV (High Speed Line) network in 2019. The Phased Network Approach allows high-speed trains to travel beyond the high-speed lines, benefit entire regions.

For example, the Paris to Marseilles trip—roughly the distance of Chicago to Memphis—took nearly six hours in 1980. Now it takes just three.

And the network is international, covering all of France and extending into England, the Netherlands, Switzerland, and Italy.

Flexible trainsets (meaning trains that operate smoothly on different kinds of tracks) are crucial to the strategy’s success. TGV trains travel at 205 mph on the newest high-speed lines.  On slower, conventional tracks, they travel at slower top speeds, but still save time with the ability to take curves faster and accelerate quickly out of stations.