A deadly crash involving a Dallas Area Rapid Transit bus driver raises more questions about whether the Texas Department of Transportation is doing everything it can to protect drivers from concrete bridge posts that sit close to the edge of local freeways.
In January, Zulita Walker died on impact off Interstate 30 at Malcolm X Boulevard in the Dallas canyon interchange.
New dashboard camera video obtained by NBC 5 Investigates shows the bus swerving from side to side and then suddenly veering off the road headed straight for a concrete bridge support post.
Despite Walker's death, TxDOT says there's no need to put any kind of protective barrier or guardrail in front of that bridge post because state and federal guidelines don't require one.
Today that post still sits out in the open in the middle of one of the city’s busiest freeway interchanges.
It's one of many locations that have safety advocates asking whether current guardrail guidelines need to change.
"It's just unimaginable that a bus can actually be torn apart like that," said Kenneth Day, president of Amalgamated Transit Union Local 1338.
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Investigators still don't know why Walker was driving too fast that night or what caused her to lose control, but it was the impact that killed her.
Day said Walker was a favorite among co-workers and colleagues at the bus drivers' union.
The post Walker hit measures just 18-and-a-half feet from the edge of the road, about the length of one car, yet there is no guardrail to prevent a driver from striking it if they happen to run off the road.
"It raises the question why not," said Day.
When asked why TxDOT would not protect install a barrier where someone has hit a bridge post and died, TxDOT's Director of Operations Randy Hopmann responded, "It might not warrant any protection."
On most freeways, current guidelines suggest a protective barrier if a bridge post is less than 16 feet from the edge of a freeway ramp.
But since this post is 18-and-a-half feet from the ramp, and there's a curb along the side of the ramp, TxDOT believes there is no need for a barrier.
"We're talking two feet. I know TxDOT would probably say where you cut it off at. We've had a fatality," said Day.
TxDOT says ultimately it is an engineering judgment as to whether a guardrail is needed. The agency said it constantly re-evaluates locations across and examines crash reports.
"Safety is our number one goal and number one priority at TxDOT," said Hopmann.
But, former U.S. Department of Transportation administrator Brigham McCown worries the state may be splitting hairs in some cases and compromising safety.
"These are guidelines. These are not one-size-fits-all rules and so you have to apply common sense. You don't want to do anything to make a potential accident worse," said McCown, who now runs a non-profit transportation safety group.
NBC 5 Investigates found 11 locations in the Dallas-Fort Worth area where an unprotected bridge post is barely beyond the distance where state and federal guidelines recommend guardrails.
On the main lanes of a freeway, current guidelines suggest guardrails should be installed if a post is less than 30 feet from the edge of the road.
On U.S. Highway 287 in Mansfield, NBC 5 Investigates found several unprotected posts that are 31 to 35 feet from the edge of road, just barely beyond the current limit.
And along westbound Interstate 20 in Kaufman County, two unprotected bridge posts measure 31 to 32 feet from the edge of the road, and do not have guardrails, even though they are just one or two feet beyond where rails are recommended.
"Clearly having these obstructions in the line of the cars' travel path at very high rates of speed is very dangerous," said McCown.
McCown questions if the 30 foot guideline even makes sense today.
The guidelines were created decades ago when freeways were less crowded, there were fewer distractions in cars and speed limits were lower than the 65 or 75 miles per hour limits on many Texas roads today.
When asked if 30 feet enough is given those speeds, TxDOT's Hopmann responded, "It's based on statistical probability. It's a zone that provides an opportunity for recovery."
In an email, the Federal Highway Administration said, "30 feet is a distance that only accommodates a certain portion of all run-off road crashes under 'laboratory conditions' so to speak."
Current guidelines have been created from tests that found 80 percent of cars that ran off the road could stop within 30 feet from the edge of at test track.
But, the other 20 percent of drivers would still likely hit the post.
Kenneth Day believes it's time to take a closer look at the guidelines and time for TxDOT to re-examine the location where Zulita Walker died.
"We should go back and review any type of rule that has a potential to save a life," said Day. "You know, we should not have to wait until there's another fatality."
NBC 5 Investigates has learned the guidelines are being re-examined on a national level.
The American Association of State Highway Transportation Officials, AASHTO, is the group that writes the national standards known as clear zone guidelines.
In an email to NBC 5 Investigates an AASHTO spokesman said, "A National Cooperative Highway Research Program study is currently underway to provide improved guidance in this area."
It may be a couple of years before any final decisions are made.
Meanwhile, TxDOT said it will install new protective barriers in at least five freeway locations identified by the NBC 5 Investigates team. At those locations, unprotected bridge posts were clearly closer to the road that the current guidelines recommend.