A Smart Work Zone (SWZ) System Implemented During an Interchange Reconstruction Project on I-35 in Kansas Cost Approximately $1.65 Million.

An economic analysis of SWZ system deployment costs in Johnson County, Kansas.

Made Public Date


United States

Summary Information

A significant level of engineering effort is required to integrate commercial off the shelf products into an effective and reliable smart work zone system. Each work zone can have a unique set of needs and challenges depending on the project setting.  The impacts of queue length, for example, can vary greatly between project sites. Consequently, the amount of time and effort required to develop control logic for a particular smart work zone system can vary greatly resulting in a wide range of deployment costs.

In 2014, The Kansas DOT implemented a smart work zone (SWZ) system that included queue warning, automated variable speed limits, estimated travel time information, and alternative route detour information along a on a 1.48 mile stretch of I-35 at the Homestead Lane interchange which was being constructed. 

The overall cost of the SWZ system was estimated at $1,650,000.  Major cost drivers included the lease/purchase of portable message systems and ITS software upgrade activities and data analysis required for site-specific system customization efforts.

The following table includes a break-out of capital costs for construction.

SWZ Construction Costs


Capital Cost

Variable speed limit signs (7 units) 


Variable message trailers (18 units)


Trailer-mounted cameras (60 units)


Trailer-mounted traffic sensors (22 units)


Software/consulting (lump sum)


ITS software upgrade (lump sum)




Of these costs, $746,500 represent purchased hardware costs for equipment that can be reused in future projects. Kansas DOT estimates that the equipment will be depreciated over 5 years at a usage rate of 75 percent.



System Cost

SWZ for interchange construction project: $1.65M