PennDOT today announced that over the next several months, crews will paint more than 120,000 miles of traffic lines that will help guide motorists on state roadways.
When temperatures warmed to 50 degrees and above, PennDOT’s 21 paint crews as well as contract painters began the mammoth task of applying approximately 700,000 gallons of white paint and 1 million gallons of yellow paint – enough to fill 435, 4-foot deep, 12-foot diameter, above-ground swimming pools – to Pennsylvania roadways.
PennDOT paints lines to increase safety and visibility for motorists, with department forces primarily painting road and highway lane-dividing lines. Paint crews also paint STOP road marks and some railroad grade crossing marks.
To help ensure traffic lines are visible in varying weather and daylight conditions, approximately 12 million pounds of recycled glass beads will be applied to the paint while it is still wet to make the paint reflective. Heated to 110 degrees Fahrenheit, the paint dries in as little as 90 seconds.
Traffic lines are repainted on most state roadways once a year because vehicle traffic, winter precipitation and winter maintenance activities wear away the paint’s visibility. Interstates are typically repainted twice a year due to higher traffic volumes.
Lines are painted day or night depending on air and surface temperatures as well as humidity. Painting typically occurs from April through October when the weather is warm and dry, as high humidity or lower temperatures will increase the paint’s drying time. Higher-volume roadways will typically see lines painted outside of commuting hours or at nighttime.
The width of the lane lines on interstate and other limited-access highways is six inches, while the center and edge lines on most state highways is four inches wide.
PennDOT urges motorists to exercise caution and follow at least 250 feet behind line painting equipment.