Publication Detail

How We Can Have Safe, Clean, Convenient, Affordable, Pleasant Transportation without Making People Drive Less or Give Up Suburban Living


Research Report

Suggested Citation:
Delucchi, Mark A., Kenneth S. Kurani, Jayoung Koo (2002) How We Can Have Safe, Clean, Convenient, Affordable, Pleasant Transportation without Making People Drive Less or Give Up Suburban Living. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-02-08-rev.1

Acknowledging that there have been many efforts to plan towns and transportation systems to better accommodate walking, bicycling, small vehicles, and other modes that can mitigate the impacts of automobile use, we take what we believe is a distinctive approach: the complete separation of high-speed, high-mass vehicles from low-speed, low-mass vehicles on a city-wide scale. Instead of having a single road system that serves everything from 50 lb. children walking at 2 mph to 150,000 lb. trucks traveling at 65 mph, we propose to plan new towns with two separate road systems, segregated according to the mass and speed of the modes. Cut points of 25 mph top speed and 1000 to 1200 lb. maximum curb weight will distinguish low-speed, lightweight modes (LLMs) from fast, heavy vehicles (FHVs). LLMs include any mode of transport under the mass and speed limit: pedestrians, bicycles, pedicabs, mopeds, motor scooters, motorcycles, golf cars, minicars, and so on. FHVs range from the conventional cars, trucks, and vans we drive every day to the tractor-trailers that deliver most of the goods we buy. As we delineate later, the physical infrastructure of the LLM network can range from an undifferentiated narrow lane that handles all LLMs (where traffic volumes are very low) to a multi-lane roadbed for motorized traffic with a paved bicycle path and an unimproved pedestrian path alongside (where traffic volumes are high). FHV roads will be similar to present conventional roads.

With this new infrastructure plan, we propose to design new communities that are accessible, safe, clean, and cohesive.

Our approach is distinctive at several levels. First, we are start by accepting that many people want to live in single-family homes, in relatively low density, and get around mainly in automobiles (whether LLMs or not). We design a town that accommodates those preferences, yet at the same time offers qualitative improvements in safety, esthetics, travel pleasure, infrastructure cost, social organization, pedestrian space, and so on. Second, in order to accomplish this we separate travel according to kinetic energy of modes. Finally, we develop a particular land use and transportation infrastructure layout that accomplishes what we want.
First published September 2002, revision published October 2010.  Replaces ITS-Davis publication UCD-ITS-RR-02-08.