INTERURBAN AND CROSS COUNTRY WORK. 203 
must be taken to double truck cars. The importance of 
this has been emphasized by several serious accidents from 
attempting high speeds with single trucks. 
So in the natural course of evolution a fine type of 
double truck car, similar to that used on many large urban 
systems has come to be used for most interurban service. 
Such a car is well shown in- Fig. 107. It is, save in size, 
closely similar to an ordinary railroad car, having the same 
  
  
FIG. 108. 
general interior arrangement. Itis forty feet long, ves- 
tibuled at one end, and is provided with special air 
brakes. 
Another recent interurban car partly open and partly 
closed (a favorite construction on the Pacific Coast) is 
shown in Fig. 108. This is rather lighter and five feet 
shorter than Fig. 107, and like it is provided with air 
brakes. 
At interurban speeds, electric or air brakes are almost 
a necessity and on the later roads are quite generally pro- 
vided. As a rule too, the wheels are larger than the 
thirty-three inch size now standard on most street rail- 
ways, thirty-six and forty-two inch wheels not being in-