Pavement Preservation: Timing of a Seal Coat

We are often asked, “When is the best time to seal coat a new asphalt concrete pavement?”  Our thinking has evolved from four to five years to one or two years after paving.  The reasoning is the early seal coat application seals the surface porosity before too much oxidation has […]

Pavement Performance: What is Going on Here?

From a cursory glance of the photograph, you could think mud had dropped from a pickup truck.  An experienced engineer see that the light-colored markings are mineral fines (the powdery portion of crushed rock) being leeched out of the pavement structure by subsurface water pressure. The source could be, excess […]

Accessible Curb Ramp: Noncompliance

The above photograph is of a non-compliant curb ramp where the side slopes are too steep and there is not a flat landing area. When looking at it more closely we determined a standard perpendicular ramp wouldn’t fit. The sidewalk is 8 feet wide and installing a typical curb ramp […]

Accesible Parking Dimensions

The photograph presents a nonstandard striping layout. A reasonable person would measure the stall and access-way from center of the double stall striping to the center of the next stall stripe. It appears this is a 9-foot stall with a 5-foot access-way. Depending on the state (and the inspector) the […]

Traffic Calming

Here is an attractive traffic calming installation using differing natural materials to make a visual barrier; create a rough texture with a slight hump; and increase road noise.  This has a nicer appearance than a yellow speed bump or hump. A raised crosswalk is another calming technique.  The raised sidewalk […]

Basic Concepts: Drainage

The typical pavement is a roadway – a long, relatively narrow strip of pavement which drains to structures along the curbs or out towards ditches. Water is not likely to remain on the pavement surface for long periods. Even water that gets into the pavement layer through cracks will flow […]

Basic Concepts: Heavy Vehicles

The typical parking lot is designed to carry light loads – passenger vehicles. There will be delivery trucks, garbage trucks, and maybe, buses. If your pavement has failures with cars passing over it, there are serious problems. Trucks and buses are a different matter.  There was a rule of thumb […]

Basic Concepts: General Problems of Large Paved Areas

We design and try to build a uniform pavement structure (see above) to cover a site that is not homogeneous.   Our most recent example of land resisting being covered happened after several days of heavy rainfall in south Texas. The photograph presents a five-year-old pavement which appears to have […]