PUBLIC THOROUGHFARES 219 



relatively closer together. Sometimes a space is 

 left in the middle of a street for planting and a road- 

 way constructed on either side. There are some ad- 

 vantages and some disadvantages in this arrange- 

 ment. The chief advantage is the ample room given 

 for the spread of tree branches and for having effec- 

 tive groupings of shrubs. The disadvantages are 

 the larger expense both for construction and main- 

 tenance and the narrowing effect in the appearance 

 of the street. For instance, if the street is narrow 

 with a parkway in the center, the road-bed on either 

 side should be not less than sixteen feet in width, 

 making a total width of pavement for the street of 

 thirty-two feet, while if the road-bed were in the 

 center, twenty-four feet would have as much ca- 

 pacity for traffic as the thirty-two feet in two roads. 

 The appearance of the roadway twenty-four feet 

 wide in the center with ample parkways on either 

 side would be more beautiful and give a more dignified 

 effect than two narrow roadways with the street 

 space divided into two lanes by the planting in the 

 center. With a broad parklike street, having a 

 width of one or two hundred feet, the two roadways 

 would be appropriate, and, with a still wider street, 

 even three roads would be advisable, the center one 



