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Portland is a PR machine for light rail & streetcar

Here are Some Facts About Portland Oregon          

One-Way Streets safer then Two-Way Streets




Studies were conducted from the 1930's to the 1970's of "before"  and "after" conditions as cities switched from two-way to one-way streets. Almost universally they found that one-way streets had 10-20% lower accident rates than when previously two-way. Most significantly, pedestrian accidents plummeted by 30-60% (Pages A-126; A-162, Source 1; Pages 7-2 to 7-8, Source 2; Source 3; Page 28, Source 4; and Chapter 10, Source 5). As one traffic safety expert noted: "Conversion from two-way to one-way street systems has consistently been found to reduce pedestrian accidents" (Source 6).


Nothing the City of Portland has done to reduce pedestrian accidents in the past 70 years has been as effective as implementing one-way streets. When the City of Portland converted most of its downtown street system to one-way in the late 1940's it found a 50% decline in pedestrian accidents, a decline in auto accidents, higher speeds, better traffic flow, and what seemed like emptier streets (because of the wider gaps in traffic), These results were typical of the many cities that made such conversions. All forms of transportation benefited: pedestrians the most, but also buses, autos, trucks, and bicycles. It has proven to be a win-win  proposition where implemented.


Since 1980 several one-way streets have been converted back to two-way flow in downtown areas. In 1986 Denver converted seven streets on three one-way  couplets. Average intersection accident rates increased 37.6% while average mid-block accident rates increased 80.5%. The City report noted that  accident rates were up on all three couplets "as is expected with two-way operation" (Pages 23 and 29, Source 7). Lubbock, Texas in 1995 converted two streets back to two-way. Overall accident rates increased there 41.6%  (Source 8).


One-way operation permits much better traffic signal progression for smoother traffic flow. This results in traffic moving at regulated speeds with less stop-and-go driving. Less fuel is consumed and there is less air pollution. One-way signalized operation also tends to cluster traffic into "platoons" with wide gaps between them . This makes it much safer and faster for cross street traffic, bicycles, and pedestrians to cross major streets.


Another benefit is in use of space. Because one-way streets move more traffic per lane than two-way streets cities with one-way systems need to devote less space to roadways. Four lanes of a one-way couplet carry as much traffic as a seven-lane two-way street. The one-way dynamics leading to superior safety and capacity are similar to why three-way intersections work better than four-way ones. A grid with only one-way streets has only two-way intersections.




FHWA - Federal Highway Administration (USDOT)


1) "National Highway Safety Needs Study, Appendix A", Research Triangle Institute, March 1976 (DOT-HS-5-01069).


2) "One-Way Streets and Reversible Lanes", Synthesis of Safety Research Related to Traffic Control and Roadway Elements, Volume I, Research Triangle Institute, March 1976 (FHWA-TS-82-232), December 1982.


3) Oregon State Highway Department, "A Study of One-Way Routings on Urban Highways in Oregon", Technical Report #59-4, April 1959.


4) Dr. Charles Zegeer, University of North Carolina, "Pedestrians and Traffic-Control Measures", National Cooperative Highway Research Program, Synthesis of Practice, #139, November 1988.


5) Peter A. Mayer, Chapter 10, "One-Way Streets", Traffic Control and Roadway Elements, Their Relationship to Highway Safety, Highway Users Federation for Safety and Mobility, 1971.


6) Dr. Charles Zegeer, University of North Carolina, "Engineering and Physical Measures to Improve Pedestrian Safety", from 1988 WALK ALERT Program Guide, National Pedestrian Safety Program.


7) City of Denver, "One-Way Street Monitoring Study, Phase 1 Conversion Report", January 1990. (The seven streets were Grant, Logan, Washington, Emerson, Downing, Marion, & Ogden Streets. Data on accident rates is from pages 15, 23, and 29).


8) City of Lubbock, "Main and 10th Street Accident Analysis, Before/After Study", 1998.




Oregon State Highway Department, A Study of One-Way Routings on Urban Highways in Oregon, Technical Report #b 59-4, April 1959,


The attached two Excel tables are extracted from the data shown in the most comprehensive study I have found on two-way to one-way conversions and provide a snapshot summary of the safety impact of converting major two-way streets to one-way flow. The study was the Oregon State Highway Department, A Study of One-Way Routings on Urban Highways in Oregon, Technical Report #b 59-4, April 1959, Salem, Oregon. This study examined “before” and “after” accidents and traffic volumes in twelve cities in Oregon from the 1930’s to the 1950’s. Because of the large sample size, variety of communities, and differing circumstances of each one-way couplet implemented during this period, this landmark Oregon study provides very comprehensive data on the safety impact of one-way streets and is the most definitive study I could find on this subject.


The tables provide not only the impact for each individual one-way couplet but a weighted average summary of the composite impact of all of them on the state highway system. The results are definitive and quite similar to those obtained in many large city studies of two-way to one-way conversions on city streets during this same period and later. While speeds and flow rates generally increased, overall accident rates declined by over 24%. Injury accidents declined by 26.1%. This debunks the theory that higher speeds inevitably lead to higher accident rates. The opposite is the case in one-way conversions because traffic flow is simpler, has fewer turning conflicts, and allows a higher degree of motorist concentration on fewer issues. Even more impressive is the impact on pedestrian accidents. The pedestrian accident rate declined 37.6%, considerably more than the vehicular accident rate. This same result is also evident in the major city studies. Pedestrians benefit the most from one-way street systems. Again, this debunks prevailing “traffic calming” claims that converting one-way streets back to two-way would makes them “more pedestrian-friendly”, the over-worked cliché phrase used throughout North America. This is rue only if one’s idea of friendliness is to have more pedestrians hit by vehicles.


ODOT1959AccRates1-W.xls   ODOT1959Summary1WRpt.pdf   Full Report


Crosswalks Can Be Dangerous!


A detailed study of the intersections showed that " pedestrian accident ratios " and "crosswalk use ratios " tend to cover a range of values . But,  in general, the study showed that in terms of usage " approximately twice as many pedestrian accidents occur in marked crosswalks as in unmarked crosswalks.


Of particular importance were the findings, based on 5 years of accident experience at 400 unsignalized intersections, that pedestrians in the 25-44+ year age group had no accidents in unmarked crosswalks, but were involved in 25 accidents in marked crosswalks . The 65-69 year age group showed a similar pattern with no accidents in unmarked crosswalks, but 13 accidents in marked crosswalks . Also of concern was the fact that during this 5 year period 49 pedestrian accidents occurred in marked crosswalks during the 5-7 p .m. time interval but during this time no accidents occurred in unmarked crosswalks.


This, plus other evidence, suggests that the poor accident record of marked crosswalks is not due to the crosswalk being " marked " as much as it is a reflection on the pedestrian's attitude and lack caution when using the marked crosswalk . For this reason marked crosswalks should not be installed unless they are truly warranted.



PEDESTRIAN CROSSWALK STUDY, Accidents in Painted and Unpainted Crosswalks, Project PS 2-001, by Bruce F . Harms

City of San Diego, California, Police Department, Traffic Bureau, Public Works Department, Traffic Engineering Section

August 1970


Sacramento: One Way Streets OK for business!

In Portland, Oregon*, which on March 1, 1950 established a complete grid of one--way streets in the central west side business area, accidents were greatly reduced . In 1951, compared with 1 .949, all types of accidents at intersections were reduced 51 per cent and, between intersections, 37 per cent . The corresponding figures for pedestrian accidents alone, were 46 and 50 per cent.





Portland: Pedestrian accidents down by 46-50%

As a whole I believe Sacramento business men will tell you that while they may have questioned the advisability of having one-way streets in the beginning, they are now almost 100%, in favor of them.

Letter from Retail Merchants Association of Sacramento


On several occasions, semi-trucks were observed abruptly stopping to yield to pedestrians. While these drivers were obeying traffic laws, this situation increased the risk of a “multiplethreat” collision when the truck yielded in the near lane. Even when these trucks did yield at the advance stop bar, the size of the trucks blocked the sight distance for both the pedestrian and any motorists in the far lane. Some pedestrians were observed stopping mid-crossing and “peeking” around the truck to see if the far lane was clear. One near “multiple-threat” crash was observed when a school bus yielded in the near lane and a vehicle in the far lane nearly collided with the crossing pedestrian.


Crosswalks Can Be Dangerous - II!



Final Report, SPR 304-321, July 2005, Oregon Department of Transportation, Research Unit and Federal Highway Administration



In summary, conversion from two-way to one-way street systems has consistently been found to reduce pedestrian accidents,

because it can greatly reduce the complexity of crossings for pedestrians and allows motorists to pay more attention to crossing

pedestrians . Where one-way street systems are feasible in terms of traffic-circulation patterns, improved pedestrian safety

is a likely result.

Conditions Where One-Way Streets Are Most Beneficial


Conditions Where Least Beneficial or Possibly Harmful








Sacramento found a 62 percent reduction in pedestrian accidents

No Two Ways About It:

One-Way Streets Are Better than Two-Way (download)   (Local PDF)

by Michael Cunneen and Randal O’Toole