98 COMMISSION OX BUILDING DISTRICTS 



Statement by Mills E. Case, Secretary, Police Department, 

 July 24, 1916 

 High buildings congest streets 



I would respectfully report that after careful study of the data at hand 

 I am convinced that high buildings are important factors in causing street 

 accidents and that the presence of business houses and factories in a resi- 

 dential district increases the probability of street accidents. 



Street accidents increase with congestion 



There are so many factors tending to cause accidents that it is a matter 

 of some difficulty to state fairly how much or how little any one factor 

 should be blamed. I have not had as much time as I should like for the 

 study of this interesting problem in its details, nevertheless I believe that 

 the main points are well established and trust that the following considera- 

 tions will make this clear. 



I have selected ten precincts in Manhattan which fall into three groups : 



I — Precincts with factories and business with a large population : 35th, 

 39th, 43d, i. c, the Upper East Side above 79th Street, population 416,000. 



II — Precincts with very considerable business and a large population : 

 7th, 13th, 15th and 17th, i. c, the Lower East Side from Manhattan Bridge 

 to 14th Street, population 458,000. 



Ill — Residential districts with a small amount of business : 36th, 40th 

 and 42d, i. c, the West Side above Cathedral Parkway (110th Street), 

 population 213,000. 



In the first group the number of accidents per 1,000 of population 

 during the first half of 1916 was 1.70; in the second group, 2.21; in the 

 third group 1.43. The population in thousands per mile of street in these 

 groups is approximately 7, 10 and 12, respectively. From this it appears 

 that accidents per 1,000 inhabitants increases rapidly as congestion (popula- 

 tion per mile of street) increases; hence, increase of height of buildings 

 increases accidents. 



Mixed occupancy increases street accidents 



The question of mixed use is complicated with that of congestion, but 

 a study of the individual precincts in the following table will help to dis- 

 entangle it : 



Precinct 



Miles of 

 Street 



14.5 



23. 



17. 



Population 

 (000 Omitted) 



Population 

 Per Mile 

 of Street 



Accidents. 



First Hall 



1916 



Accidents, 



Per M 

 Population 



35 



39 



43 



127 

 192 

 97 



8,760 

 8.350 

 5.700 



7,140 



163 

 363 



182 



1.28 

 1.89 

 1.88 





54.5 



416 



708 



1.70 



7 



13 



IS 



17 



11.33 

 10. 



IS. 

 11.28 



72 

 112 

 155 

 119 



(,,340 



1,200 



1(1.3(1(1 



10,600 



128 



325 

 372 

 187 



1.78 

 2.90 

 2.40 

 1.57 





47.61 



458 



9,820 



1,012 



2.21 



36 



40 



42 



25. 

 30. 

 51.28 



87 

 66 

 60 



3. ISO 

 2,200 

 1,170 



142 



76 

 86 



1.63 



1.15 

 1.43 





106.28 



213 



2,010 



304 



1.43 



