- [Presenter] Departments of transportation nationwide
use the highway safety manual
to implement safety interventions when designing roadways.
But roadways in Texas are often unique,
compared to their counterparts in other states.
Working with the Texas A&M Transportation Institute,
the Texas Department of Transportation
has adapted the manual
to better meet design challenges
unique to the Lone Star state.
- So we have the highway safety manual now.
It was published in 2010.
It has, like, safety performance functions
that are generally used in project-level decision-making
to estimate the average crash frequency by severity type.
And also, when the new roads are proposed,
we need these safety performance functions
to estimate the crashes on them.
- Because highway safety manual matter was developed,
at least most of the matters were developed,
based on the data from other states.
So, we thought it's logical
to, either develop local models,
or local calibration factors,
to use it more effectively for Texas projects
- We assembled, like, a sample data sets,
for rural two-lane highways, rural multi-lane highways,
rural freeways, and urban arteries.
These data sets were assembled
for both segments and intersections,
because they behave differently with respect to safety.
So, unlike segment database,
Texas do not have an inventory of an intersection database.
So our team used the HERE traffic analytics data,
and we developed a statewide database
of about 900,000 intersections.
In addition, we do not have the frontage road SPFs,
so we developed new frontage road SPFs
and as well the ramp SPFs in this, in this study.
The other point, is Texas is a big state.
We all know it.
And then we have the regional differences.
The segment in one region
may have a different safety performance
than a segment in a different region.
So, to account for these regional differences,
we developed region-specific adjustment factors, as well,
you know, to estimate the crashes in a specific region.
- So that data driven analysis approach,
we are hoping that this will improve the knowledge,
and also it'll end, you know,
it'll help us to develop safer design.
And as a result of this,
we will have a safe transportation infrastructure.
- The methods that we developed
in the state will help the state
in selecting the projects that improve safety,
by accurately estimating the traffic crashes.
And again, the state has a vision, like a vision,
vision zero goal, to have zero fatalities by 2050.
So, the techniques that we developed
in this research will help in reaching those goals.
- [Presenter] For more information,
and to find the publications for this project,
please visit the text dot research library
at the link shown below.