282 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1956 



Figure 9. — Geographical distribution of traffic in Los Angeles County. Area of circles is 

 proportional to the number of vehicles; each square represents 16 square miles (4x4 

 miles). 



2.4 

 2.0 



1.6 



1.2 



0.8 



0.4 



8 10 12 



246 8 10 12 246 



HOUR OF DAY 

 Figure 10. — Example of hourly variation of traffic volume in Los Angeles 



