Manhattan Delivery Truck Traffic (IMAGE) Rensselaer Polytechnic Institute Caption A federal study led by Rensselaer Polytechnic Institute is helping make Manhattan streets cleaner, less congested, and more profitable for businesses by shifting daytime delivery truck traffic to after normal business hours. Credit Rensselaer Polytechnic Institute Usage Restrictions Please include photo credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.