Engineers and Planners responded with…

Traffic Calming

Context Sensitive Design

Learning from History: The old way

Traffic calming adds some new tricks to our bag of design options but….

We can learn a lot about designing good roads by looking at the old way of design

the old way1. Roads fitted the context

Traffic Calming

Contribute to livability and multimodal transportation by limiting speed and/or

volume of vehicular traffic

And to our health according to the USA Today….

Bicycling Commuting and Traffic Calming

Very few people commute by bikes in the USA…

Modal Split for Bikes

USA

Germany

Netherlands

Bicycling Commuting and Traffic Calming

… except in a few places with the facilities

Modal Split for Bikes

USA

Davis, CA

Germany

Netherlands

Bicycle Safety and Traffic Calming…. the rate of fatality per trip in USA is very high

Bicycle Fatality Rate per Million Trips

USA

Germany Netherlands

Pedestrian Safety and Traffic Calming Percentage of Pedestrians Killed Doubles for Each 5 mph Increase in

Speed(USDOT – National Highway Safety Administration,1999)

010203040506070

<20 21-25 26-30 31-35 36-45 46+

Travel Speed, mph

Perc

ent o

f Ped

s Ki

lled

All Peds

Elderly

Traffic Calming Measures vertical deflection (speed humps, raised pedestrian crosswalks and

intersections)

narrow traffic lanes small turning radii at intersections extensions to the pedestrian realm (raised

crosswalks and intersections and curb extensions) chicanes roundabouts and traffic circle Diverters and Closures bike lanes and bike boulevards

Vertical Deflection

Portland DOT Speed Study 14 ft Bumps http://www.trans.ci.portland.or.us/trafficcalming/reports/reports.htm

Portland DOT Speed Study 14 ft Bumps http://www.trans.ci.portland.or.us/trafficcalming/reports/reports.htm

Portland DOT Speed Study 22 ft Bumps http://www.trans.ci.portland.or.us/trafficcalming/reports/reports.htm

Portland DOT Speed Study 22 ft Bumpshttp://www.trans.ci.portland.or.us/trafficcalming/reports/reports.htm

Narrow Traffic LanesPortland, Or

Narrow Traffic LanesWest Hartford

Extensions to the Pedestrian Realm

Trinity College, Hartford

Extensions to the Pedestrian Realm

Portland, Or

Extensions to the Pedestrian Realm

Durham, New Hampshire

Chicane

Traffic Circle

Traffic Circle

DiverterBerkeley, California

DiverterBerkeley, California

Bike BoulevardBerkeley, California

Bike BoulevardBerkeley, California

Traffic Calming Design for Emergency Vehicles

http://www.trans.ci.portland.or.us/trafficcalming/Emergency/emergency.htm

Two of the main traffic calming devices potentially affecting emergency vehicle operations are bumps and traffic circles.

Portland (Oregon) DOT has done extensive research on emergency vehicles and traffic calming.

Emergency Vehicles and Traffic CalmingTraffic calming slows down all

vehicles including emergency response vehicles – this is a potential problem when there is an extensive system of traffic calming devices.

However, it should be pointed

out that a properly designed network should compensate for lower speeds because routes are generally shorter.

Traffic Calming Design for Emergency Vehicleshttp://www.trans.ci.portland.or.us/trafficcalming/Emergency/emergency.htm

Changes that have been made in the Portland traffic calming regulations to better accommodate emergency vehicles

Add ‘emergency response route’ to road types in Portland DOT functional classification

Split (or offset) bump

Another good site for traffic calming and emergency vehicleshttp://www.cwdnet.com/qlc/tc_emergency_padot.htm