What Does a Work Zone Cost Users?
Did you know that motorists encounter an active work zone one out of every 100 miles? Or that work zones on freeways account for 10 percent of overall delays?
Improving America’s roads is vital to our nation’s success in the long run. However, it can also create inconvenience for drivers and local businesses in the short-term.
That’s why the National Asphalt Pavement Association (NAPA) has developed a new work zone impact cost tool to calculate the impacts of construction. The tool allows agencies and contractors to run scenarios based on the parameters of a job and calculate various costs.
“When you have a work zone, it affects how people use a roadway,” said Auburn University’s Jeff LaMondia. The delays incurred due to road work are also accompanied by a number of costs, including costs to drivers on that road, the cost of potential crashes, and a decrease in revenue for local businesses.
“A lot of DOTs are investing in new technology to reduce delays in work zones,” LaMondia said. “With this tool, we can quantify the cost-benefit ratio for those investments.”
What Costs Does it Quantify?
The tool calculates three primary costs: road user costs, crash mitigation costs and local business impact costs.
Road user costs are costs experienced by delayed personal and freight vehicles. The tool generates a total road user cost per day, based on time lost, vehicle operating costs and emission costs to the environment as a result of additional travel time through a work zone.
NAPA primarily used both the Federal Highway Administration’s Work Zone Road User Costs final report and the American Association of State Highway and Transportation Officials’ User and Non-User Benefit Analysis for Highways as the source for these numbers.
The second cost the new tool measures is crash mitigation cost. The types of crashes and costs associated with them are evaluated using FHWA’s KABCO scale, which outlines the five types of crashes (fatal, incapacitating injury, minor injury, possible injury and property damage only) that may happen in a work zone and the associated financial cost of each.
NAPA’s tool takes into consideration work zone and driver characteristics, such as work zone geometry, traveling speed and overall volume, to figure out which type of crash on the KABCO scale is most likely to occur.
“Based on statistical analysis of work zone crashes, there is one crash per work zone,” LaMondia said. The new NAPA tool figures out the most likely crash to occur in a work zone based on its characteristics, and what the associated cost of such a crash would be.
The final cost the tool calculates is revenue lost by a local business due to reduced access to its location, also known as local business impact costs (LBIC).
“We knew anecdotally that businesses sometimes see reduced revenues when a work zone is going on, but our research really quantifies those effects,” LaMondia said. “The local user impact cost was a lot higher than we expected.”
Since most information about LBICs was anecdotal, the research team collected their own data via a paid survey capturing 770 responses from across the country. The sample group is representative of gender, region, ages and incomes, so the data can be used to return meaningful results from any region of the country NAPA’s tool may be used in.
The researchers determined consumer behaviors based on the type of trip the consumer was taking (for example, picking up groceries, attending a doctor’s appointment, or going out to eat), spending habits and journey duration.
What the researchers discovered was that a delay of 5 minutes had very little impact, while a delay of 20 minutes resulted in most consumers choosing to go somewhere else.
“You aren’t just talking abstractly about costs,” LaMondia said. “You can use numbers and data to support questions your community might have. The key takeaway here is if you can shave off even a single day, you can reduce those costs quite a lot.”
How to Use the Calculator
NAPA’s new calculator tool can be used during project evaluation to conduct cost-benefit analyses of proposed plans, schedules, material choices, work zone layout and other factors. It can also be used during project planning to identify what time of day or what day of the week the work should be completed and compare different scheduling options. It can also be used to communicate with the local community.
“If you’ve done your due diligence, you can show them the factors you’ve considered to reduce the cost to them,” he added. “You can show them that by rescheduling the project, for example, you saved them a certain number of customers who would have otherwise shopped elsewhere.”
LaMondia said the tool is also very simple to use. All calculations happen in the background, invisible to the user. He or she simply inputs a number of characteristics about the roadway, the area, and the work zone.
The tool allows users to input the roadway characteristics, like average annual daily traffic, truck volume percentage, expected weather, urban or rural, lane width and speed limit, among others.
Once all of the characteristics are added, the user clicks calculate to run the simulation. Within 30 seconds, the tool runs 2,000 simulated vehicles through the scenario and then scales the vehicle volume to match that of the work zone to generate the total work zone impact cost.
The tool is now available here.