SEPTA Blocking System

The first digits shown in figure 1-2 represents the depot which the bus comes from.

Figure 1-2:

SEPTA allocates all of their Bus, and Trolley fleet on a 4-digit block system. This helps the transportation authority to help track down buses as well as tell where buses on these block runs originate from. The block allocations are shown in the charts below.

An example of the block system

On the New flyer buses, the block system is displayed as shown in figure 1-1

Figure 1-1

The first digit of the number represents which depot the bus came from as listed above the ‘9’ means the bus is from Callowhill depot. This is a block off of the first 44 block on weekends, usually the fourth digit of the block number starts off at a 0,  1, or 5.

Case 1: The first trip on a particular route usually starts at the very first block number digit which the route is assigned to. For example, block number “9651” meaning that 9651 is the block number of the very first bus to pullout from Callowhill operate on the route 44. The next bus to pull ou usually goes in Numerical order.  So the next bus to show up would be “9652”.  This is the case on many routes. However on some routes, this is simply not the case. It really all depends on how the route is setup, for example sometimes, it may skip a number and go from 651 to 653, then back to 652, then 654.

Case 2: The block numbers on trippers may be out of order with the rest of the system. The block system on the route 65 (Callowhill side) starts at 9601 and ends at 9614. Theses are typically the blocks are that used on the 65, at one point a tripper was assigned on the 65 to do one run in the mornings. It’s block number was 9634. The block number 9634 was still in the allocation for the route 65, however, it’s out of order with the other blocks on the route.

Case 3: For the suburban routes, the block numbers used during the week are different then the block numbers used on Saturdays, and Sundays. For example, on the route 125, blocks 4700-15, may be used on the weekdays, however on Saturdays, the blocks used are from 4720-4739. On Sundays it would be from 4751-4760. As noted from the allocation Chart, the route 125 allocation covers 4700-4799. This is well within range.

Case 4: For some routes, mainly southern, the block numbers are completely random. However they are still bound to the block allocation in the routes.

Many blocks numbers are interinterlined between two or multiple routes. For a example,  #9906 block on Sundays may start out on the Market-Frankford Line, however on it’s second half, it operates on the route 52. The 9906 block number will still remain there. Until the block run is completed.and the bus has pull into the depot.

Here’s a complete list of where the block numbers will start at starting with Allegheny:

Allegheny

Callowhill

Comly

Frankford

Midvale

Southern

Frontier