Originally Posted by ardecila
If Metro ever decided to stop using herbicide on their rights-of-way, they'd soon get all sorts of drought-tolerant vegetation to soften the edges. Germany banned herbicides, so their tracks and railyards have all sorts of growth between tracks, etc. The plants actually soak up water, which lessens the load on the drainage system, and their roots reduce erosion in the ballast. Usually we think of killing weeds as a necessary part of maintenance, but it's purely a matter of aesthetics.
Average yearly rainfall for Munich = 31.9 inches
Average yearly rainfall for Frankfurt = 22.1 inches
Average yearly rainfall for Berlin (airport) = 23.5 inches
Average yearly rainfall for Los Angeles (city center) = 14.98 inches
Average yearly rainfall for San Monica = 12.69 inches
Average yearly rainfall for Anaheim = 13.55 inches
Sources = weather.com
And from wiki.......
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than 16 inches. A common definition distinguishes between true deserts, which receive less than 10 inches of average annual precipitation, and semideserts or steppes, which receive between 10 inches and 16 inches.
The LA basin qualifies as a semidesert. Germany, on the other hand, averaging between 22 to 32 inches falls under temperate deciduous forests. Neither CA-DOT nor does Metro have to spray herbicides to kill grasses along their right-of-ways. The LA climate does that well enough.
How dry is Los Angeles really? Due to dry summers in Southern California, rainouts at Dodger Stadium are rare. Prior to 1976, the Dodgers were rained out only once, against the St.Louis Cardinals, on April 21, 1967. That rainout ended a streak of 737 consecutive games without a postponement. The second home rainout, on April 12, 1976, ended a streak of 724 straight games. No rainouts occurred between April 21, 1988 and April 11, 1999 - a major league record of 856 straight home games without a rainout. April 21, 1988, was the last of three consecutive rainouts from April 19. That is the only time consecutive games have been rained out at Dodger Stadium. If the Dodgers didn't fertilize and water their grass at Dodger Stadium, there wouldn't be any.
image source = http://users.rcn.com/jkimball.ma.ult...s/B/biomes.gif