Interstate High Speed Rail Taxonomy
Interstate High Speed Rail Taxonomy is organized by speed categories from slowest to fastest. Outside America, others would call it an Intercity High Speed Rail Taxonomy. In this narrative series, miles per hour (mph) are often listed beside kilometers per hour (kph). Note that 6.213 mph = 10 kph speeds common to High Speed Rail in other nations. — Thomas Dorsey, Soul Of America
If you’re an American planning to visit Western Europe or Eastern Asia, include a HSR ride, if only for one day. Then, you will immediately appreciate these speed, frequency and reliability stats. Afterwards, imagine how HSR would benefit your family and business back home.
If that doesn’t work for you watch this short video about French HSR development.
Slower Intercity Passenger Rail Routes
Freight-Commuter Rail routes can support 50-81 mph (80-130 kph) Top Speed: Diesel engine trains run on them; they have old & slow “Legacy Rail” infrastructure (major curves, old bridges & tunnels, level railroad crossings, old track switches, old electric power, signaling & communication systems); most have 1-track tunnels, followed by alternating sections of 1 or 2 main tracks shared by freight, commuter and long-distance passenger trains; due to their long stopping distances, freight trains typically run 30-60 mph on them; a 3 to 4-cabin commuter train typically has 180-240 passenger capacity; commuter trains typically run every 45-60 minutes at Peak Hours, every 90-120 minutes Off-Peak; long-distance trains typically run at least 500 miles, but may run thousands of miles; an 8 to 10-cabin long-distance train has 300-350 passenger capacity; long-distance passenger trains typically run 1-3 times daily for , though some run on alternating days; both commuter and long-distance trains require taxpayer subsidy to operate.
In America, Amtrak Regional & Long-Distance trains mostly run on Freight-Commuter Rail routes.
Enhanced Commuter Rail Routes can support 87-93 mph (140-150 kph) Top Speed: Diesel-electric engine trains run on them; since diesel-electric locomotives emit a fraction of air pollutants and use battery power while in stations, they are replacing diesel engines on these routes; many routes have 2-track tunnels to match 2 main tracks, occasional Siding Track for freight trains, and a few over/underpasses at railroad crossings; freight and commuter trains still share them; though diesel-electric trains can reach 125 mph, they rarely exceed 81 mph (140 kph) without substantially more over/underpasses on these routes because an 80 mph, 8-car passenger train on level ground needs about 1 mile to stop; partly for shorter braking distance, commuter trains typically have 5- or 6-cabins that have 300-360 passengers capacity; they typically run every 20-30 minutes at Peak Hours, every 40-60 minutes Off-peak; commuter trains in these routes typically require less taxpayer subsidy.
By 2030, America will have a significant number of Enhanced Commuter Rail Routes.
Faster Intercity Passenger Rail Routes
Regional Rail Routes can support 93-112 mph (150-180 kph) Top Speed: They are upgraded from legacy rail to support electric trains that have pantographs on top; these routes overhead wires, called “catenary”, that pantographs contact to draw electric kilovolts at 1.5 kV, 3 kV, 12 kV, 15 kV or 25 kV level; these routes have more over/underpasses, street closures, 2-track tunnels & viaducts; some boost speed by 12 mph with 2-3 feet of curve easing and replacing old roadway overpass pylons that were close to tracks; they have 2 main tracks for passenger trains and a 3rd main track (see diagram below) or intermittent Siding Track for freight trains; they have modern track switches, signaling, train control & communication systems; their Regional Trains typically run every 15-20 minutes at Peak Hours, every 30-40 minutes Off-peak; commuter trains in these routes typically require the least taxpayer subsidy.
If America gets serious about Intercity Passenger Rail, all Amtrak Regional trains and many commuter trains should run on Regional Rail routes.
High Speed Rail (HSR) is next-level infrastructure for High Speed Train (HST) operations. An HSR route’s Top Speed is largely certified by the degree of rail curvature called “Minimum Curve Radii”, degree of rail slope called “Gradient”, smoothness of track and degree of signaling sophistication to handle frequent running HST. To achieve straighter routes, more tunnels, aerial viaducts and earthmoving are required. Legacy routes boost speeds 18-24 mph (30-40 kph) via 5-6 feet of curve easing and replacing roadway overpass pylons that were close to tracks. To achieve flatter routes, earthmoving and level track bedding are required. To achieve smoother rides, continuous-welded rail, concrete rail ties and precise track-shaving are required.
HSR systems require dependable electric grids feeding electric sub-systems and catenary along routes. Higher consistent voltage is required for higher speeds, Therefore, HSR systems have tighter strung catenary to supply consistent high voltage (12 kV, 15kV or 25kV) matching each nation’s operating standard. Advanced signaling & automated train control systems assist train engineers on HSR systems.
For higher speed, safety and schedule reliability, HSR systems close off small streets, build over/underpasses at all railroad crossings and install fencing on all surface track to prevent people, other animals and automobiles from crossing. These routes are designed to operate at breakeven to avoid taxpayer subsidy or at a profit.
1st Generation HSR Routes can support 130-155 mph (210-250 kph) Top Speed: They are upgraded from Legacy Rail infrastructure; mostly electric trains run on them for faster acceleration & deceleration; they have upgraded signaling, automated train control & communication systems; HST run 124-143 mph (200-230 kph) on them; a 5-cabin train conveys about 250 passengers; HST typically run every 30 minutes at Peak Hours, every 60 minutes Off-peak on them; A small percentage of these routes permit diesel-electric locomotives until the route converts to electric power systems; HST typically run at 86-90% schedule dependability on these routes.
2nd Generation HSR Routes can support 160-174 mph (260-280 kph) Top Speed: These HSR lines are a hybrid of Legacy Rail upgrade infrastructure and new high-speed infrastructure; aerodynamic HST use their dedicated high-speed tracks; they have milder curves, more tunnels & viaducts, faster track switches; they have 25kV electrical systems, plus modern signaling, automated train control & communication systems; HST run 149-161 mph (240-260 kph) on them; a typical 6 to 7-cabin HST has 300-350 passenger capacity; they typically run every 20 minutes at Peak Hours, every 40 minutes Off-peak; HST typically run at 93-96% schedule dependability on these routes.
3rd Generation HSR Routes can support 193-205 mph (310-330 kph) Top Speed: These routes are built as modern high-speed infrastructure; they have longer tunnels & viaducts for milder curves than 2nd Generation HSR Routes; their tracks are shaved for smooth rides; only light-weight, aerodynamic HST use their dedicated high-speed tracks; only HST run on them at the same 174-186 mph (280-300 kph) top speed for highest efficiency and capacity per hour; a typical 7- to 9-cabin train has 360-480 passenger capacity, while 7 to 9 bi-level cabin trains enable 570-740 passenger capacity; HST typically run every 15 minutes at Peak Hours, every 30 minutes Off-peak on them; HST typically run at 97-98% schedule dependability on them; Japanese HST is an exception with 16-cabin trains having 1,323 passenger capacity, running every 5-10 minutes at Peak Hours, every 15-20 minutes Off-peak with 99.9% schedule reliability; these routes set safety standards for all transportation modes.
4th Generation HSR Routes can support 224-249 mph (360-400 kph) Top Speed: These modern routes have longer tunnels & viaducts, more earthmoving for milder curves and flatter profiles than 3rd Generation HSR Routes; their tracks are shaved for baby-smooth rides; their overhead catenary is strung tighter and more durable than 3rd Generation HSR Routes; though current HST run up to 199 mph (320 kph) on them, Nextgen HST are will run 205-224 mph (330-360 kph) on them; these routes are designed for 98-99.9% schedule dependability; a typical 9-cabin train has 500 passenger capacity, while 9 to 11 bi-level cabin trains enable 740-855 passenger capacity; these routes also set safety standards for all transportation modes.
In the rest of this series, I combine all generations of High Speed Rail routes together as “HSR” for group context, but separate generations when specificity requires. “HSR systems” refer to the combination of HSR route infrastructure, HST and operating practices.
Regional Trains & High Speed Trains
Japan, France, United Kingdom, Germany, Italy and America invested modest R&D sums on electric-powered commuter & intercity trains to reach 81-93 mph (130-150 kph) after World War II. But once Japan’s introduced the first 130 mph (210 kph) HSR system in 1964, other advanced nations coveted its speed, capacity, frequency, schedule reliability and safety.
France took engineering to another level with the fastest HST in 1981 (168 mph), 1988 (186 mph) and 2007 (199 mph), while maintaining a spotless safety record in operation. At the same time, Italians introduced wheel technology that tilts trains whose lower center of gravity and better suspension enable 6-12 mph (10-20 kph) faster speeds through curves. Later, Germany mastered integration of Regional Trains & HST in weblike, high frequency networks. Those four countries produced most HSR system innovations that other nations copy.
At very high speeds, small gaps between cabins and uneven cabin heights increase wind-drag for train vibration, noise and energy consumption. To counter those effects, Nextgen HST weigh less with small inter-cabin gaps and even cabin heights for very aerodynamic contours. Technological advancements enable HST Builders to certify Nextgen HST up to 236-249 mph (380-400 kph) top speeds. As of this writing, no HST Operator operates them above 217 mph (350 kph) to avoid substantially higher maintenance costs from wearing down rail, wheels & catenary faster.
HST Operators don’t want excessive energy costs eating profits either. A law of Physics is that wind drag scales as the cube of vehicle speed. That means an HST that requires 1X electricity to overcome wind drag at 150 mph, requires 2X electricity at 225 mph and 4X electricity at 300 mph. Nextgen HST built in this decade have lighter weight and regenerative brakes creating electricity for on-board services. They can run at 199 mph while consuming 21-22% less energy than current HST at 199 mph.
To control energy costs before introducing higher speeds, most HST Operators await utility companies adding cheaper wind, solar and geothermal energy to more efficient & reliable electric grids. They also await HSR Builders introducing more efficient electric sub-stations along routes.
For international boasting rights in 2017, China was the first nation to introduce Nextgen HST running 217 mph (350 kph) on 4th Generation HSR route. An equally remarkable feat of engineering is that you can balance a coin on the train’s window sill at 217 mph. Other HST Operators announced plans to introduce Nextgen HST running at 205, 211, 217 or 224 mph on 4th Generation HSR route over 2023-27. Benefiting from more materials R&D, their Nextgen HST should also be slightly quieter.
Speed isn’t the only attraction for HST passengers. Excluding some Asian countries where HST have 5 narrow seats across a row in Coach Class, most HST have 4 comfortable seats across a row in Coach & Business Class, large windows & window shades, better seat lamps, better WiFi, electric outlets & tray tables at each seat, well-stocked cafe cabins, larger restrooms and more wheel chair accessibility than Regional trains.
Italian HST Operators took passenger amenities to another level. They introduced First Class service that has premium leather reclining seats, 3 or 2 seats across a row, private group seating, Quiet-Cabins and the option for upscale dining.