Fees for Using the Patented Parallel Flow Intersection

The parallel flow intersection (PFI) is a patented design. Please contact Greg Parsons before opening a PFI to traffic. We encourage any DOT planning to implement a PFI to involve GFParsons prior to commencing final design and involve us as a subconsultant to the prime consultant–GFParsons does not act as the Engineer of Record.

NOTE: The patent is not a copyright. Anyone is free to include information on the PFI in presentations, publications, studies, even final design and construction without restriction. The patent means a PFI cannot be opened to traffic without GFParsons permission. But any DOT considering using the PFI is encouraged to involve GFParsons as early in the process as possible to get the benefit of our expertise and avoid any possible future conflicts.

GFParsons seeks a fee for using the PFI as described below depending on the situation:

If the DOT approaches (or consultant) GFParsons to use a PFI for a project, GFParsons will seek engineering fees (time and materials) for technical advise and quality assurance during the design and construction stages of the project.

Scope of GFParsons involvement is negotiable.

NOTE: GFParsons will not serve as the Engineer of Record (EoR). The DOT will need to follow their normal final design process and hire GFParsons separately as a consultant or through the EoR as a subconsultant.


If GFParsons approaches the DOT and proposes the PFI for inclusion in an ongoing project, the following conditions apply:

1) The project does not have identified alternatives.

In this situation, GFParsons seeks engineering fees as described above as if the DOT first contacted GFParsons.

2) The project does have alternatives identified.

In this situation, GFParsons is proposing the PFI as an alternative that will result in significant project savings for the public. GFParsons considers the PFI alternative as value engineering and seeks the following, whichever is greater:

2a) 50% of the project savings before Federal income tax.

2b) Engineering fees for time and materials as described above.

NOTE: In case there is significant uncertainty in the project cost and PFI savings is expected to be large, GFParsons will base the fee on a $0.01 per trip (after Federal income tax) over the design life of the project based on projected AADT volumes.


If you have questions or believe your situation is not addressed above, please contact Greg Parsons using our contact page.