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Basics of Urban Street Networks. Norman W. Garrick Lecture 3.2 . Impact of Street Network Design. Research shows that street network design can impact Traffic safety Choice of Mode Vehicle Miles Travel Health outcomes Character and value of communities. versus. Safety Impact
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Basics of Urban Street Networks Norman W. GarrickLecture 3.2
Impact of Street Network Design Research shows that street network design can impact • Traffic safety • Choice of Mode • Vehicle Miles Travel • Health outcomes • Character and value of communities
Safety Impact Risk of Severe Injury or Fatality* versus Chance of being Severely Injured 30% Higher Chance of being Killed 50% Higher *Given that an injury occurred
Impact on Safety Odds of Dying in a Road Accident based on Intersection Density* 1 in 200 1 in 500 *Given that an injury occurred
Impact on Mode Choice Percentage of People Walking, Biking orTaking Transit
Impact on Mode Choice Percentage of People Walking, Biking orTaking Transit Effect of Intersection Density for Cul-de-sac Network
Impact on Mode Choice Percentage of People Walking, Biking orTaking Transit Effect of Intersection Density for Gridded Network
Guidelines for Street Network Design A good street network should have • High Density The density can be measured by intersections per square miles or my block size or other related parameters • Good Connectivity at all geographic scales (from regional to neighborhood) Not all streets should be connected at all scales but the streets that connect region wide should be frequent (no more that ½ mile apart). • Great variety in streets types The street network should have streets that vary from very busy to very quiet, from mostly commercial to mostly residential. In general, the busier streets should be the more commercial and the more regional. While the more residential streets should be shorter/more local. • No Restrictions on the types of streets that are connected to each other For example, small neighborhood streets should connect to big regional streets with no restrictions.
The Streets of Prenzlauer Berg Schoenhauser Allee The main street Prenzlauer Allee The second main street Pappelallee A neighborhood shopping street Raumerstrasse A neighborhood shopping street Goehrener Strasse A residential street
Greigenhagener Strassesimilar to Goehrener StrasseA residential street