TGV - Leader of the Phased Network Approach
Europe’s first dedicated high-speed line—the LGV Sud Est (or Southeast High Speed Line)—shows the wisdom of the Phased Network 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.
For example, the Paris to Marseilles trip—roughly the distance of Nashville to Kansas City or San Francisco to San Diego—took nearly six hours in 1980. Now its close to 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.