(air whooshing)
- [Narrator] Making rural highways as safe as possible
is a continuing effort by transportation researchers
and The Texas Department of Transportation.
With the number of motorists increasing across the state,
this effort is a priority.
This research determines when turning lanes need to
be included at intersections
near passing lanes on Super 2 corridors.
- [Marcus] TxDOT has been building Super 2 highways
for more than two decades now.
And they provide great opportunity for passing
for vehicles that
are through vehicles that are traveling long distances.
But what that means, is they don't focus as much
on intersections and driveways
but as you build more passing lanes,
the need becomes greater to have some guidance
on what to do with passing lanes near intersections.
- So what we're trying to do by looking
at the scenario is to decide what the safest way
to address that scenario is to address
both the safety of through traffic and turning traffic
and to limit the amount of roadway delay at those areas
to be able to expedite the flow of traffic through there.
- The biggest piece of the research involved
the team recording and observing operations
at some locations with intersections near
and within passing lanes on Texas highways
to see what was going on
and using those recordings,
we were able to process the data
and turn that into material that fit into simulation models.
- From their results of the simulation that they created,
they were able to virtually optimize what
the best scenarios are as far as the locations
of passing lanes around these intersections,
or, if it's necessary to have a location
where there's going to be left turns
within the Super 2 section,
how to best handle that scenario.
- [Marcus] What the research has shown is that you can
in fact have the passing lanes and the intersections in
in close proximity, and they do work.
You don't have to avoid intersections
with your passing lanes, but you do need to have
that separation.
And so in particular, there should be a separation of
at least 1500 feet between an intersection,
and the end of a passing lane
to provide room for the turning vehicles
and the merging vehicles to stay separated.
But what we've also found, is that it does provide
not only operational benefit, but a financial benefit,
benefit cost that was performed, showed great benefit
in
the operational benefit
reduction of delay,
reduction of crashes,
compared to the cost of building the infrastructure.
- At this point, with the guidance,
and the observations that the researchers did,
and with the model that they were able to produce,
I do feel that the next step is going to be implementation
and working some places up that we can look
at implementing the technology out on the roadway.
- [Narrator] For more information,
and to find the publications for this project,
Please visit the TxDOT Research Library
at the link shown below.