Hal JohnstonHal Johnston has been a past Certified Professional Estimator (ASPE) for 30 years and is a licensed (inactive) general contractor in the State of California. He is a Professor Emeritus of Construction Management at California Polytechnic State Univerity, San Luis Obispo, California, and was a Visiting Professor in the Department of Construction Management and Economics, Civil Engineering at Czech Technical University in Prague (CVUT) for a number of years and continues to teach in the department as an outside lecturer. Read More Read Less