Editing Grid plan (section)

===Safety===
Perceived and actual safety play a role in the use of the street. Perceived safety, though perhaps an inaccurate reflection of the number of injuries or fatalities, influences parents' decision to allow their children to play, walk or bike on the street. Actual levels of safety as measured by the total number of collisions and the number and severity of injuries are a matter of public concern. Both should inform the layout, if the street network is to achieve its optimum use.

Recent studies have found higher traffic fatality rates in outlying suburban areas than in central cities and inner suburbs with smaller blocks and more-connected street patterns.<ref>{{cite journal | pmc=1448007 | pmid=12948977 | volume=93 | issue=9 | title=Urban sprawl as a risk factor in motor vehicle occupant and pedestrian fatalities | year=2003 | journal=Am J Public Health | pages=1541–5 | last1 = Ewing | first1 = R | last2 = Schieber | first2 = RA | last3 = Zegeer | first3 = CV | doi=10.2105/ajph.93.9.1541}}</ref><ref>{{cite web |url=http://www.virginia.edu/topnews/releases2002/lucy-april-30-2002.html |title=Danger in Exurbia {{!}} U.Va. Study Reveals Outer Suburbs More Dangerous Than Cities |access-date=2006-09-03 |url-status=dead |archive-url=https://web.archive.org/web/20060903234004/http://www.virginia.edu/topnews/releases2002/lucy-april-30-2002.html |archive-date=2006-09-03 }}</ref>

An earlier study<ref>Eran Ben-Joseph, Livability and Safety of Suburban Street Patterns: A Comparative Study (Berkeley, CA: Institute of Urban and Regional Development, University of California, Working Paper 641, 1995)</ref> found significant differences in recorded accidents between residential neighborhoods that were laid out on a grid and those that included culs-de-sac and crescents. The frequency of accidents was significantly higher in the grid neighborhoods.

Two newer studies examined the frequency of collisions in two regional districts using the latest analytical tools. They investigated the potential correlation between street network patterns and frequency of collisions. In one study,<ref>Using Macrolevel Collision Prediction Models in Road SafetyPlanning Applications Gordon R. Lovegrove and Tarek Sayed Transportation Research Record: Journal of the Transportation Research Board, No. 1950, Transportation Research Board of the National Academies, Washington, D.C., 2006, pp. 73–82</ref> cul-de-sac networks appeared to be much safer than grid networks, by nearly three to one.
A second study<ref>Sun, J. & Lovegrove, G. (2009). Research Study on Evaluating the Level of Safety of the Fused Grid Road Pattern, External Research Project for CMHC, Ottawa, Ontario</ref> found the grid plan to be the least safe by a significant margin with respect to all other street patterns.

A 2009 study<ref>{{cite journal | last1 = Dumbaugh | first1 = Eric | last2 = Rae | first2 = Robert | year = 2009 | title = Safe Urban Form: Revisiting the Relationship Between Community Design and Traffic Safety | journal = Journal of the American Planning Association | volume = 75 | issue = 3| pages = 309–329 | doi = 10.1080/01944360902950349 | s2cid = 153379995 }}</ref> suggests that land use patterns play a significant role in traffic safety and should be considered in conjunction with the network pattern. While all intersection types in general reduce the incidence of fatal crashes, four-way intersections, which occur regularly in a grid, increase '''total and injurious crashes''' significantly. The study recommends hybrid street networks with dense concentrations of T-intersections and concludes that a return to the 19th century gridiron is undesirable.

Stringent adherence to the grid plan can cause steep inclines since the topology of the land is not taken into account. This may be unsafe for drivers, pedestrians and bicycles since it is more difficult to control speed and braking, particularly in winter conditions.