(soft instrumental intro)
- [Presenter] When the Texas Department of Transportation
builds a roadway, it always strives to balance mobility
and safety during design and maintenance of the facility,
but as populations and road use change over time,
that initial design, whether it's the lane configuration
or the cross sections, often needs to change
in order to better accommodate traffic.
Researchers with the Texas A&M Transportation Institute
recently completed a project working with TxDOT Districts
to update the state's roadway cross sections guidance
for the department's Roadway Design Manual revisions.
- TxDOT has long been looking for a way to best utilize
the pavement and the right of way that they have
on the roadways and as traffic volumes change,
the idea is do we have enough lanes and the right type
of lanes that best meet the needs for that roadway?
- So, most of the research was done just using data,
crash data in ADT information and looking at
maybe some before and after data on some roads
that had undergone some conversions
to see what happened after.
- It was primarily a review of existing guidance,
research findings and conclusions, not only from research
that was done here in the state by TTI and others,
but elsewhere across the state
and even some international guidance.
- So, the real benefit of the research has given
the department a better way to balance safety and mobility.
So, you would think instinctively you always need
more lanes out there, but sometimes by reducing lanes
or adding a two-way left turn lane in lieu of maybe
two through lanes can provide some additional
safety benefits and that safety benefit
may be of better value to both the public
and the department.
- The key piece of implementation is the table
that we've recommended, either in its current form
or with any additional changes that TxDOT might see
to refine it to be included in the next edition
of the Roadway Design Manual,
which is already under some review.
And so, the timing is good
and that this fits with other edits
that they're already considering.
The biggest benefit to TxDOT is that it builds
on previous research to help them identify
fairly, in a fairly straightforward manner
what the optimal cross section
for a given roadway should be,
streamlines that and optimizes the chances
that TxDOT is putting the best
and most appropriate number of lanes on the roadway
for what's needed.
For the driving public, the benefits then
are that they have a roadway
that better serves their needs, that provides
a turning lane where there's lots of driveways
or maybe it provides passing where there's not
very many passing opportunities on a current two-lane road
where a super two is appropriate,
and hopefully, gets them from place
to place safer and more efficiently.
- [Presenter] For more information
and to find the publications for this project, please visit
the TxDOT research library at the link shown below.