By Sarah Zarzecki, contributing author
When it comes to major transportation construction projects, how do you price safety? For the Colorado Department of Transportation, the $30 million expenditure in traveler safety was worth it during its lengthy – both in construction time and distance – Interstate-25 South Gap project.
The transportation agency, its general contractor, and associated consultants worked with the Colorado State Patrol (CSP) and local emergency response agencies to combine conventional management of traffic methods with new smart work zone technology to decrease response times, reduce accidents, and ultimately promote safer travel in a long and tight construction zone.
The approach was motivated by anticipation of increased traffic incidents and the deaths of two state patrol officers working the stretch.
I-25 is a major national north-south transportation corridor, a lifeline between Denver and Colorado Springs, the state’s two largest cities. More than 80,000 vehicles a day use the former four-lane divided expressway, one designed in the 1960s for much slower speeds than used today.
Approximately 120,000 vehicles are expected to use it a day by 2040. Planners knew that construction of this 18-mile-long project, which would add toll lanes both ways and other improvements from Castle Rock to Monument Hill north of Colorado Springs, would inhibit traffic and lead to increased accidents. So, the state and local emergency responders threw the book at safety, using new technology for the first time. Construction of the I-25 South Gap, as it was known, was completed ahead of schedule over four years at the cost of $419 million.
According to Rocky Mountain Construction magazine, the increased congestion and population growth have led to safety issues. Before the project began, over a three-year span, there were 14 fatalities along the route, including two state troopers who were killed while responding to incidents in this corridor. That same three-year span saw 1,500 incidents and 900 of them resulted in injuries.
CDOT’s safety toolbox included traditional methods, such as lower construction speed zones, electronic signage, higher fines, and stepped-up enforcement. But the toolbox was expanded for the first time with the deployment of such measures as an onsite traffic operations center, responsive and portable variable speed limit signs, a construction truck warning system, pan tilt zoom cameras, courtesy tow trucks and most importantly, a twice-monthly emergency responder meeting that coordinated construction progress with responder communications and response plans.
Did it all work? Average emergency response times in the corridor were cut in half from 40 to 20 minutes. Traffic accidents rose 60% during the first year of construction; 11-foot-wide lanes had just 1- or 2-foot shoulders from barriers and the few interchanges on the stretch meant as much as 5 miles of travel without egress opportunity.
Although exact statistics weren’t available, state patrol officers estimated that the combined safety and traffic incident management effort lowered accidents by approximately 15% than normal, the result of quicker response times and fewer secondary accidents, which are usually more deadly.
“You had key stakeholders from multiple disciplines,” said CSP Captain Lawrence Oletski. “Together, these moving parts worked seamlessly together to help this project finish ahead of schedule and under budget. The key to our success was the bi-weekly traffic incident management team meetings that covered all bases. These meetings helped review and plan to help reduce the rate of injury and fatal crashes.”
Managing Incident Responses
Stanley Consultants worked as a subcontractor to Jacobs, and with its client, the Colorado Department of Transportation (CDOT), and its contractors, they increased safety and improved response times for emergency crews during the prolonged construction of additional lanes in the heavily traveled I-25 stretch between Denver and Colorado Springs.
As part of the overall maintenance of the traffic plan, Stanley Consultants engineers analyzed and explained preliminary construction designs and schedules to best manage traffic incidents and emergency responses. Regular meetings with the contractor, CDOT, state and county enforcement and fire rescue helped plan for an emergency response, such as where ingress and egress would be during a specific construction phase and how the communication would flow between agencies.
The client spent extra on the overall safety and traffic incident management plan to employ the following measures to save lives:
- Bi-weekly emergency responder meetings
- Two free courtesy patrol tow vehicles
- Project operations center, first in Colorado
- Emergency pullout areas
- Portable traffic speed monitors
- Smart work zone technologies
- Portable variable speed limit signs, first construction project in Colorado.
- Portable changeable message signs
- Truck entering and exit system
- Queue detection system
- Travel time indicator system
Like with any project, two critical activities for success were planning and reacting during construction. For planning, the contractor brought the preliminary design and shared its views on risks, constructability, and the construction schedule, breaking it into parts. For example, new elements were funded and added to the project, including an essential climbing lane on notorious weather-plagued Monument Hill and a new bridge repair and replacement program.
The traffic incident management team worked closely with the overall maintenance of traffic planners to study and understand district boundaries; followed an incident classification procedure that identified incident severity and allotted appropriate resources; created high-level detour routes for highway shutdowns and developed a communications tree.
Most importantly, the plan included the first-ever use in Colorado of a project operations center located at the project field office. Teams at the project operations center monitored traffic volumes and incidents through the mounted camera system 12 to 16 hours a day, with the state traffic operations center handling the overnight hours.
If best-laid plans mean nothing after the battle starts, it’s all about adjusting, and that’s what happened. The best tool was the bi-monthly emergency responder meetings facilitated by the contractor. As lane closures occurred, the team discussed how they would affect response access points, critical because of the lack of interchanges along the stretch.
If something wasn’t working for one of the agencies because of lack of space, for example, perhaps a wider turn area would be requested. Barrier locations might be changed; hot spots were identified by the traffic monitors; towing operators contributed suggestions.
The meetings were more of a “check your ego at the door” type of discourse, said Rich Martin, deputy chief of the Castle Rock Fire and Rescue Department.
“Everyone also was willing to listen and make any plan we needed to function without trying to diminish any one group, company or agency,” Martin said. “Also, the continual updates and information were shared by the public information officers and communications group. This way we could all make plans, if needed, to adjust responses. I believe we showed during this project that including all involved and allowing the ability to adjust plans ensured the success of this project.”
As seasons changed, the assorted team changed practices. Every winter brought a different lane configuration. Where would chain-up stations be located? How would road closures be managed? Was the communication flow adequate during storms? The project endured the infamous bomb cyclone in March 2019 with 90-mph winds, a 60-car pile-up and multiple highway closures. Lessons were learned during negative events, such as how to conduct search and rescues along the stretch during storms. The communication during and between emergency response meetings remained essential, State Patrol’s Oleski emphasized.
“This project started pre-Covid, endured Covid, and came out on the back end of Covid,” Oleski said. “When you don’t have the ability to see people face to face, and you are left with a one-inch by one-inch square, the key to any success is picking up the phone and calling people.
“E-mail isn’t effective. Talking to someone on the phone, especially someone you have known for years, conveys a sense of purpose. This project was not a 9 to 5 Monday through Friday project. Being available at all times helped this project succeed like no other project I had ever been a part of in my 25-plus years with the Colorado State Patrol.”
Using the traffic incident management approach helped reduce emergency response times by half. The intent was to reduce dangerous secondary incidents and clear traffic for the public to travel more efficiently. The program almost certainly saved lives, officials say, and will serve as a model for future state projects.
“Yes, it most definitely did (improve safety and safe lives) in my opinion,” Castle Rock’s deputy fire chief Martin said. “The opportunity for all involved agencies and companies to sit and pass on information and ideas made this project more efficient and safer.” R&B
Sarah Zarzecki, P.E., P.M.P., is the Colorado transportation department manager for Stanley Consultants. She can be reached at [email protected].
