^56 



BELL SYSTEM TECHNICAL JOURNAL 



To develop this relationship it was necessary first to determine a typical 

 distribution of trafiic throughout the day, i.e., the ratio of the busy hour to 

 each of the other hours. Actual delays experienced on a particular group 

 may deviate somewhat from those developed herein to the extent that the 

 actual distribution varies from the typical distribution. 



The probable total day circuit delays are derived from Figs. 5 and 6 and 

 from a typical distribution of traffic based on a five-day record on each of 20 

 groups in Ohio and 24 groups in Illinois. 



It will be noted that the above distribution shows a busy hour which is 

 12.5% of the total 24-hour day but that the weighting factors are based on a 

 total day of 14 hours. This corresponds to the normal service observing 

 period so that the results will be comparable with the overall total day speeds 

 obtained from service observations. 



The total day delays for Tables T-1 to T-5 for each size of group were 

 computed as illustrated in the following sample calculation: 



