Highlighted in AASHTO's 2019 "Research Impacts: Better – Faster – Cheaper​" https://research.transportation.org/High-Value-Research-Projects/

"Benefits
• Improved curb inlet equations for TxDOT which will result in safer inlet designs. In particular, less
ponding at sag inlets will improve traffic safety at thousands of locations as the new equations
propagate through new design and construction.
• Inlet design and construction cost reductions up to 15 percent. Assuming an estimated $4,000 per
15 ft. long inlet, this is a savings of $4,000 x 0.15 = $600 per inlet.
• Improved curb inlet equations for FHWA, which will result in safer inlet designs, particularly for curb
inlets with locally depressed gutters. Depending on various scenarios, both over-designs and underdesigns
will be minimized, resulting in both construction cost savings and less risk of dangerous
flooding or hydroplaning situations. New design equations for curb inlets with locally depressed
gutters can reduce inlet design and construction cost up to 18 percent for 15 ft. long inlets. This is a
cost savings of $4,000 x 0.18 = $720 per 15 ft. long inlet.
• These cost savings are in addition to improved future traffic safety at tens of thousands of locations
across the country. Assuming a 50% efficiency improvement in surface drainage, there will be less
likelihood of vehicles hydroplaning." --p.131