Recommended treatments can be shown for query results by clicking on the Recommendations tab in the results window. A table of countermeasures applicable to your locale and the type of location (e.g. signalized intersection, roadway, etc.). In California, the included countermeasures and values correspond to the latest HSIP cycle. Each countermeasure includes a description and categorization, a crash reduction factor (CRF), life expectancy, annual and life benefit, the number of applicable crashes and several other fields.
Additional fields may include the opportunity of systemic categorization (how easily the countermeasure can be applied across a network), the percent of federal funding reimbursement, the project type and location type. The entire table can be exported to a PDF or to an Excel spreadsheet.
An example screenshot is shown below:
How Applicable Crashes and Benefits are Calculated
Locations are aggregated to three main categories within the location type field:
- Signalized intersections
- Non-signalized intersections
For top intersection locations, intersection histories or general queries with an intersection signalization filter used, either the signalized or non-signalized intersection countermeasures depending on the signal status will be shown in the table. For corridor queries or general queries without an intersection filter, roadway countermeasures will be shown. Queries by report numbers will show all countermeasures. This will allow a user to evaluate countermeasures based on their desired location type. An example usage for a query by report numbers would be to aggregate collisions around numerous intersections to generate a combined benefit as part of a systemic analysis.
Tip: Ensure you set the specific collision date time frame using one of the other query types before loading a list of report numbers since the most recently used time frame will be used to calculate the annual benefits.
Each collision will then be evaluated for their applicability to the individual countermeasures. Many countermeasures are applicable to all collisions, but restrictions can be based on injury severity, ped/bike involvement, day/night status, animal involvement, emergency vehicle involvement, etc. All collisions are evaluated for all countermeasures and the count of applicable crashes is shown in the No. of crashes column. Each applicable crash benefit is then summed to calculate the annual benefit. For California HSIP, the benefit values are derived from the local roadway safety manual.
Adding Project Costs / Calculating BC Ratio
A project cost field is also included which allows direct input by the user. Clicking on any project cost cell will show an input option. After entering a value, the corresponding B/C ratio field will be calculated based on the life benefit and project cost:
After entering project costs, you can sort by the B/C ratio field to rank the best potential projects.