HvyOilGuy wrote:
Electric trains are best for main routes, but it would be too costly to put rails everywhere. I was thinking vans could be used for feeder routes, or to fill in gaps in the system.

I think the rule of thumb is that if a transit line averages more than 12,000 riders a day, factoring in weekends and holidays, it is better to electrify.

Houston's Harris County Metropolitan Transit Authority ("Metro") is a classic example of why electric traction is better than internal combustion on key routes. This was already evident a year and a half ago, before the latest round of stratospheric diesel prices.

On January 1, 2004, HCMTA opened their 7½-mile express streetcar line from downtown to the south side of town. This line was built and eighteen low-floor light rail cars were acquired from Siemens in Sacramento for $324 million. This included street and sidewalk improvements. Since Tom Delay blocked FTA funding for the line in Congress, the line was built entirely from local sales tax revenues.

Initially, there were more than 100 collisions between motorists and light rail cars. Camcorders on the light rail cars showed that the motorists were at fault in all but one instance. There was one fatality when a motorist ran a red light in downtown Houston into a light rail car traveling at 35 miles per hour. After a study by Metro, the City of Houston, TxDOT and A&M University, the traffic lights were synchronized to the light rail operation. The traffic lights now hold red in all directions for ten seconds while the rail cars pass through an intersection. Collisions are now rare. Note that you are 2½ times more likely to die in a traffic accident in metro Houston that you are on the average in the US. Since then, the city of Houston has installed red-light cameras at 50 intersections, as well as several suburban cities.

Ridership on the line skyrocketed in the following years, from 16,000 on a weekday to 45,000 today. Saturday ridership is now 15,000 per day and Sundays and holidays, 12,000. The line carries over 11 million people per year, as of last year. Even though there was a fare increase this year, rail car boardings are increasing.

The rail line allowed Metro to truncate 15 parallel bus lines at light rail stations. Eighteen light rail cars freed up 45 buses for use elsewhere.

During the same period, in addition to truncating major bus lines into light rail stations, Metro slashed service on dozens of secondary bus routes in outlying areas, citing increased operating cost and low ridership. Since 2002, due to bus service cuts and substitution of MetroRail for travel in the Main Street Corridor, Metro's diesel consumption has declined by 12% from 15,903,948 gallons to 14,502,611. Yet, in the same period, the cost of diesel paid by Metro has soared over 160% to $39 million:

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Metro have not yet released their 2008 budget (their fiscal year begins on October 1st), but you can imagine that their fuel cost is much higher now.


By contrast, even though Houston has just about the highest electric cost in the country due to deregulation, the cost of electric propulsion of light rail is really quite nominal. Regarding energy efficiency, look at MetroRail's energy consumption per passenger mile based on Metro FY 2007 budget (PDF):

I'll assume that the average trip length for a passenger on the 7½ mile line is 2½ miles, which may be an understatement:

Number of boardings: 10,807,000
Average trip length: 2½ miles

Annual MetroRail passenger miles 27,017,500

Power consumption for MetroRail propulsion: 7,236,000 KWH

Budgeted cost per KWH: 11.3026¢

Total Annual Power Cost: $817,856

Annual Power Cost ÷ Passenger Miles = 3.027¢ per passenger mile

The only less energy-intensive way of getting around Houston is walking or bicycling.


Although Metro's rail propulsion cost will go up higher than expected, motor fuel prices have swelled light rail rider totals, so ~3¢ per passenger mile cost will probably hold steady. The budget assumed the planned fare increase would lower ridership. That didn't happen. There are now over 11 million boardings per year.

In summary, the capital cost of electric rail is considerably higher than the capital cost of building dedicated internal combustion bus lanes. But the depreciable lives of electric rail assets are far longer than those of bus assets. The maintenance cost of electric rail vehicles is much lower than that of internal combustion buses, since electric traction motors have less moving parts and run at far lower temperatures. Electric rail requires a considerably lower BTU-equivalent per passenger mile than motor buses. Electric traction vehicles accelerate faster than ICE buses, increasing passenger throughput and on-time performance. Rail cars can be coupled together as in Houston, lowering labor cost per passenger mile.

So the bottom line is, spend the money up front on electric traction or get killed by motor fuel prices by relying on internal combustion for heavy transit lines.

Houston:
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