Example Project for Systems Engineering Process –

Los Diegos Fast Bus Signal Priority Project




(Note: This first page is not part of the SERF – it helps explain how the project developed.)


Project Objectives:

Increase transit ridership by substantially reducing travel time for existing express buses on the heavily traveled Happy Street corridor in the City of Los Diegos, California (in Riverside County).


Local and Express SCAMP buses run every five minutes along this major arterial roadway.  Studies show that these buses encounter 20 minutes of delay at the 40 traffic signals on the route.   To support the Mayor’s new “Go Transit” initiative, Los Diegos DOT (LoDDOT) and Southern California Associated Mobility Providers (SCAMP) aim to reduce this delay to 10 minutes or less for express buses.


Preliminary Planning:

During their monthly golf game, the CEO’s of LoDDOT and SCAMP agreed to the city’s first application of preferential treatment for transit vehicles.  Technical staff at each agency then conducted a Feasibility Study, including research and site visits to nearby cities, to learn about the current technologies and alternative project designs that have been used elsewhere, plus typical costs. 


Description in TIP:

“Preferential Treatment for SCAMP buses on Happy Street in Los Diegos, from Atlantic Road to Pacific Avenue (10 miles) – $500,000.”


Description in the Regional ITS Architecture:

This project appears in a generic form in the Inland Empire Regional ITS Architecture –

“IE-13: Transit Vehicle Signal Priority” [See page G-3]



(The actual SERF appears on the next page.)


(Los Diegos Fast Bus Signal Priority Project)

This form needs to be filled out for all ITS projects.  For all High Risk (Major) ITS projects, this completed form needs to be submitted to FHWA for review and approval prior to PE authorization (Phase 1 PE authorization). 


For all High Risk (Major) ITS projects, a Systems Engineering Management Plan (SEMP), which includes the seven items below, must be submitted to FHWA for review and approval, prior to PE authorization for component detailed design (Phase 2 PE authorization).  Required FHWA approvals are limited to High Risk (Major) ITS projects.


For guidance in filling out the seven items below, see last part of this exhibit.


1.       Identification of portions of the Regional ITS Architecture being implemented:

Project IE-13: “Transit Vehicle Traffic Signal Priority (local agencies)” in the Inland Empire Regional Architecture (RA), page G-3.

Subsystems: roadway and transit vehicle; Arch. Flows: Local Signal Priority Request.


2.       Identification of participating agencies roles and responsibilities:

SCAMP will install/operate equipment on buses to issue requests for traffic signal priority [RA, 4-21]

LoDDOT will upgrade signal controllers to receive requests and provide appropriate priority [RA, 4-21]

We will define detailed roles and responsibilities in the Concept of Operations step.


3.       Requirements definitions:

The high-level requirements, as defined in the Regional Architecture, are:

SCAMP Transit Vehicles  [RA, 5-19]

  • Request signal priority from equipment on the roadside, as appropriate

LoDDOT Roadside Equipment  [RA, 5-11]

  • Receive vehicle signal priority requests and send to traffic signal controllers   
  • Provide signal priority at signalized intersections when activated (as appropriate)

We will identify detailed requirements during the project definition phase.


4.       Analysis of alternative system configurations and technology options to meet requirements:

Our Feasibility Study indicated that the project budget will constrain our options to “local control” at each intersection, because SCAMP buses will not have AVL until 2012 and LoDDOT will not have a centralized traffic control system until 2011.  We will analyze: (1) alternative approaches and technologies for local signal control, (2) alternative schedule-adherence policies for the SCAMP buses, and (3) options for communications between bus and traffic signals.


5.       Procurement options:

If this requires two separate contracts, we will hire a Systems Manager to coordinate both projects and perform acceptance tests.  We will also consider having one agency lead the project and hire a System Integrator for implementation, plus a System Manager for project definition and acceptance testing.    We believe that all components will be “off the shelf” with no software development, so we plan to use fixed-price contract(s) for system installation, and probably T&M for the Systems Manager.


6.       Identification of applicable ITS standards and testing procedures:

We will probably use the same equipment and communications protocols as were used by nearby cities who have implemented BSP with SCAMP. This enables SCAMP buses to be assigned on any routes.


7.       Procedures and resources necessary for operations and management of the system:

LoDDOT will train their equipment maintenance staff to repair the upgraded signal controllers.

SCAMP will repair bad transmitters by swapping out a bad unit and sending it to the factory.

In both shops, the existing staff can handle the additional workload.  LoDDOT will have final authority to decide on when and how much extra green time is allowed at each intersection.  Full details regarding procedures and resources needed for O&M will be developed during the project definition phase.