Register Your RSAP
   Installation Tips
  Example Case Workbooks
  User Submitted Examples
RSAPv3 is free and there are no restrictions on copying or using it.  It is, however, a good idea to register so that you can receive updates and other information as it becomes available.  Click here to register.
These are the Excel macro-enabled workbooks for the cases described in the User’s Manual.  It may take some time to open up Excel over the internet so you should save these locally and open them on your computer. 
RSAPv3 is written as a series of Microsoft Excel macros.  RSAPv3 will run on any Windows computer running Excel 12 (office 2007) or better and will run on both 32 and 64 bit computers.  RSAPv3 has been successfully tested with Windows7, Windows XP and Vista.  
The following section includes some examples of common problems people experience while instaulling RSAP.  Please refer to the installation tips page for a full list.
If you have an example that you would like to share, please email it to the project team using the following E-mail link.
Email The Project Team
   Overview of RSAP 

RSAP is an encroachment-based computer software tool for cost-effectiveness evaluation of roadside safety improvements originally developed under NCHRP Project 22-9(1).  Subsequently, some improvements were made, bugs corrected and patches installed under NCHRP Project 22-9(2).  A third NCHRP project, 22-9(3) was initiated but never completed.  Various releases of RSAP have been distributed with the AASHTO Roadside Design Guide (RDG) since the 2002 edition.  This version of RSAP (i.e., RSAPv3) was developed under NCHRP Project 22-27 which was completed in 2012.

The analytical model behind the encroachment-based approach uses a series of conditionally independent probabilities representing vehicle roadside encroachment events, the conditional probability of a crash given a roadside encroachment has occurred, the probable severity of crashes that are likely to occur and the expected benefit cost ratios of various roadside design alternatives. Based on the sequential nature of these conditional probabilities and the assumption that they are independent, the RSAPv3 is basically structured into the following four modules, similar to its predecessors:

Encroachment module,

Crash prediction module,

Severity prediction module and

Benefit-cost module.