Assuming that the average number of vehicles per day and the average tonnage per day are the same throughout the year as during the periods of counting, we deduce the following results:
| Location of bridges | Period of count | Street cars | Heavy wagons | Light wagons | Carriages | Automobiles | Pedestrians | [39]Gross tonnage | [40]Total value |
|---|---|---|---|---|---|---|---|---|---|
| 6th St. | 1909 | 534,652 | 333,829 | 474,171 | 57,013 | 147,095 | 9,608,406 | 13,240,010 | [41]1,879,140,750 |
| 9th St. | 1909 | 738,650 | 90,812 | 150,490 | 6,205 | 9,709 | 1,877,268 | 14,732,130 | 2,201,473,500 |
| 16th St. | 1909 | 115,851 | 202,429 | 1,991,988 | 967,544 | 102,201,375 | |||
| 30th St. | 1909 | 58,875 | 60,919 | 3,979 | 2,664 | 577,320 | 398,430 | 44,233,500 | |
| 43d St. | 1909 | 42,522 | 42,559 | 5,147 | 11,351 | 681,710 | 311,090 | 32,478,500 |
| Location of bridges | Passenger vehicles | Delivery vehicles | Single trucks | Double trucks | Pedestrians | [39]Gross tonnage | [40]Total value |
|---|---|---|---|---|---|---|---|
| Seventh Street | 29,273 | 351,400 | 19,929 | 75,555 | 2,127,585 | 1,159,084 | 149,862,600 |
Railroad Bridges.—The bridge carrying the heaviest traffic is that of the Pittsburgh, Fort Wayne and Chicago Railroad, a part of the Pennsylvania System, which forms one of the links in the main line of this railroad system between the East and West. Across this bridge are carried each year about 2,750,000 passengers, 32,000 tons of mail, and 53,000,000 tons of freight and general railroad traffic, besides about 2,135,000 pedestrians,[42] making it one of the greatest throats of commerce in the country. This is a double deck bridge of 4 tracks, 2 tracks on each deck, with a wide footway on the lower deck. It is to be noted that the amount of traffic passing over this bridge is about 25 times as much as that which floats on the water beneath it, and is far higher in quality and value per ton.
The other railroad bridge crossing the river within the city limits is the Thirty-third Street viaduct of the Baltimore and Ohio Railroad. This is a link in the Baltimore and Ohio Railroad between the East and the West and carries an enormous traffic amounting each year to about 217,000 passengers and 24,330,000 tons of freight, express and other trains.
Uniting this with the traffic over the Fort Wayne bridge of the Pennsylvania we have crossing the Allegheny River on the two railroad bridges a gross amount of 77,330,000 tons, and 5,102,000 passengers and pedestrians, with a value of tonnage traffic estimated at approximately $4,957,000,000.
APPENDIX II
Amount and Importance of River Traffic.—The following statistics were obtained from the United States Engineers' office and show the number of boats, net tonnage and number of passengers passing Dam No. 1 in the Allegheny River during the year 1909:
| Month | No. vessels | No. passengers | Tonnage of cargoes |
|---|---|---|---|
| January | 338 | 16 | 30,889 |
| February | 358 | 18 | 30,073 |
| March | 1,055 | 25 | 81,424 |
| April | 732 | 197 | 51,457 |
| May | 896 | 1,506 | 57,269 |
| June | 958 | 1,248 | 56,324 |
| July | 901 | 2,495 | 37,888 |
| August | 868 | 2,019 | 29,102 |
| September | 1,006 | 1,681 | 36,759 |
| October | 955 | 982 | 53,622 |
| November | 789 | 616 | 42,827 |
| December | 495 | 231 | 29,086 |
| Total | 9,351 | 11,034 | 536,720 |
The following are statistics of counts taken in 1909 at the different bridges: