20 is Plenty and Other Crazy Thoughts

Earlier this year in an online forum on Reddit, I laid out my quick list about what the top transportation needs are for Roswell.  My list in no order of importance and applicable to most cities was as follows:

  • Bring MARTA Rail to North Fulton
  • Increase Street Connectivity
  • Remove Reversible Lanes
  • Build More Roundabouts
  • Drop speed on ALL residential streets to 20 mph
  • Build the Roswell Loop

Most of my suggestions focused on increasing transportation options and improving safety.  Interestingly, the one that got questioned was the point about dropping speeds on residential streets to 20 mph.  When I indicated that my rationale was for safety reasons, one commenter insinuated that this isn’t necessary because we don’t have a pedestrian death problem in our residential areas.  I agree and we should feel fortunate for that.  However, I think many a homeowner can point to multiple occasions where they have encountered drivers speeding recklessly on neighborhood streets.

Speed has a logarithmically negative effect on survival rates for pedestrians involved in collisions with cars.  A 10% increase in vehicle speed increases pedestrian fatality risk by 40-45%.  Data shows that when a pedestrian is hit by a car traveling at 20mph, they have a 95% chance of survival.  However, as the speed increases, the survival rate plummets.  When a car is traveling 40 mph, the pedestrian survival rate drops to just 15%.  This is just plain physics.  Doubling speed results in the required stopping distance quadrupling and the kinetic energy absorbed at impact is also fourfold.   We may not have a death problem here in North Fulton but nationwide, more than 30,000 people are killed in car crashes annually and an increasing percentage of those are pedestrians.  Ten times that number are seriously injured every year.  The costs to society are staggering but we accept it as a necessary evil to support our auto-dependence.

Slowing down to 20 mph is a radical idea that would increase safety in our communities for pedestrians and cyclists alike.  That said, simply lowering speed limits isn’t a panacea.  Drivers generally drive at the speed they feel safe regardless of the posted speed limit.  This comfort zone, the speed that feels safe, can also be called the design speed or the speed at which the road was designed to be safely navigable.  The philosophy of wider, safer, faster holds true here.  The wider the road is, the safer it feels at higher speeds.  This counterintuitively increases speeds which conversely decreases safety for everyone involved.  

We’ve all lived in or driven through residential subdivisions with streets wide enough to fit parked cars on each curb and two active lanes.  The problem with this is that the streets in suburban residential areas are rarely every fully lined with parked cars.  The end result of this is a dangerous design with wide expanses of asphalt that encourage teenagers to test their limits and rushed commuters to push the gas.  This would happen in this environment regardless of whether the posted limit was 30 mph, 25 mph or 20 mph.  It’s just not conducive to a slow drive.

That said, a 20 is Plenty campaign such as those that are having great success across Europe and the UK would be a bold step to create safer and more walkable cities.  The movement is slowly making its way to the US and is now under consideration in several cities and towns in the northeast.  New York City is considering it and some people have even gone around town putting up their own signs on light posts.  There is also research indicating that slower street speeds are linked to more social connections, a stronger sense of community, higher property values and increased walking and biking.  

It almost sounds like a no brainier.  So, this is how I would propose phasing in a 20 is Plenty campaign: 

  • Step 1 (year 1-3).. Give all neighborhoods and subdivisions the option to adopt a 20 mph limit.
  • Step 2 (year 4).. Adopt on all roads that have residential as  > 50% of their frontage and on any road that fronts a school or park for a quarter mile in each direction.
  • Step 3 (year 1-10 and beyond).. Re-engineer streets over time to narrow lanes and install street calming devices that would encourage slower speeds.

The next time you’re driving through a neighborhood remember that 20 is Plenty.

Rezoning Silliness

There is a rezoning battle that is coming up on Monday at City Hall and NO, it's not the UDC.  It's actually probably not much of a battle but it piqued my interest.  To me, it illustrates just how ridiculous our whole zoning process really is.  The lot in question at 1270 Strickland Rd, pictured below, is actually quite a beautiful lot.  It unfortunately abuts some ugly industrial lots to the north but that said, it has some charm.

We have a developer, Brightwater Homes of Sandy Springs, that is looking to build homes on the 5 acre parcel.  Given the current R-2 zoning, they would be able to build 14 single family units.  They are looking for a reclassification to give the parcel a R-2 Conservation subdivision classification.  The change would allow 15 homes on smaller lots while also conserving 1.79 acres as greenspace.  Additionally, the developer plans to put a walking trail on the greenspace for residents of the new homes.  

There are obvious technical differences in the classifications but come on...  1 additional home on some smaller lots??  I say that if it makes sense, looks nice and will have a positive impact on the city, then we should allow it.  But, it's never that easy and the opposition was out for the August Planning Commisison Meeting.  The notes were a bit long and a number of neighbors voiced their concerns, some valid in my opinion and some not so valid.  I've summarized and added commentary to several.

  • Reductions in Set-backs - One resident feels that the request to reduce the building set-backs will reduce the natural beauty of the parcel.  Well, putting 14 or 15 homes on that parcel is going to degrade it regardless.  If it is going to be developed, it should be designed to be the most walkable as possible and the further homes are from the street, the less walkable the environment.


  • Traffic (ALWAYS A CONCERN, RARELY AN ISSUE) - A point was made that the size of the neighborhood is increasing by 50% from 30 to 45 residences and this will cause problems at the Prospect St and Hwy 9 intersection.  I'm not sure I'm buying this.  Of course, there may be some additional traffic but it's not going to be catastrophic.  Is that intersection ackward?  Yes.  Should that be rationale to deny one extra home?  No

  • Our Children Won't Be Safe!! - Some other concerns were voiced that the increase in car volume coupled with the non-cul-de-sac design would potentially pose a danger to the children in the neighborhood.  What poses a danger to the children in the neighborhood is actually the straight-away design of Valley Dr with lanes that are as wide as the lanes on GA400.  Lane width is a major determinent of the safety of a residential or city street.  The wider, the more dangerous.  A small block is no more or less dangerous than a cul-de-sac.  


  • Nothing is Being Saved - The argument was posed that the site layout would not change much regardless of the zoning type because most of what is being conserved in the Conservation Subdivision plan is in the floodplain.  Point taken but there is something being gained in the form of a walking path and increased walkability in the site plan.

All that said, the Planing Commission has recommended that the change request be denied and the city council is voting on it this Monday 9/9.  The Planning Commission commentary centered around these points:

  • Conservation Subdivision vs Standard Zoning - They seemed to like the conservation aspect but had difficulty weighing the consequences of rezoning.  The trail was a hit but some concerns were voiced about maintenance, public access and security.


  • Why Not Fewer Lots with Bigger Homes? - This was the argument that seemed to be the deal killer.  Most of the commission members thought that fewer homes would be a better fit for the neighborhood.

My opinion is that the R-2 Conservation Subdivision site plan with 15 lots provides for a more walkable design.  I do take exception to the 12' lane widths which are wholly unnecessary for this type of road regardless of what the DOT and Fire Department tell you but that's a whole different story.  The jury is still out on whether the architecture will amount to much of anything.  You be the judge.

R-2 Site Plan

R-2 Conservation Subdivision Site Plan


Welcome to West Roswell... Where We Hate Pedestrians

I came across this sign today and it absolutely drove me crazy.  This spot is along highway 120 just west of the Coleman Rd traffic light on the north side of the highway at the entrance to Willeo Creek Apartments and Roswell Pointe condominiums.

First, as you probably know, I think we have too many redundant signs here in Roswell.  When you are in a lane that has a gigantic right arrow painted on it that ends after the intersection, do you really need a sign to tell you that the lane is a right turn only?  COME ON!

Next, you probably won't notice but there are at least 7 different signs in this photo: Right Lane Must Turn Right, No Walking on Grass, Do Not Enter (faces the other way), Stop, Divided Highway, Yield, No Outlet.

HOLY MOLY!!  This is sign overload.  Are we as a society so stupid that we need this kind of signage to keep us safe.  A driver can figure everything that is indicated in each one of those signs from context.  In my opinion, there are two necessary signs here.  The Stop sign and the Yield sign.  All others could and should go.

Those issues are both secondary however.  The sign that I have the biggest issue with though is the NO WALKING ON GRASS sign.  There are no sidewalks here but the intersection you are looking at serves as the only access point for Willeo Creek Apartments and Roswell Pointe condominiums.  It is less than a quarter mile walk from a Kroger, Starbucks, Texaco and multiple restaurants.  

It would probably be nice to walk over to those businesses every once in a while and I'm sure some people do.  In fact, I witnessed a forbiden pedestrian actually walk on that grass while I was there taking the picture above.  I was only there two minutes. 

What this No Walking on Grass sign (and ther are others on the property) is suggesting is that pedestrians either shouldn't walk here or they should take their chances on the road.  Whatever entity put this sign up, is implying that they care more about the look of their grass than they do about a human life.  

I have two requests:


  • First, the signs suggesting that people cannot walk on grass that abuts a major state road where sidewalks are not an option should be removed immediately.
  • Second, a sidewalk should be installed asap.


If you feel this is unwarranted or if you agree with me, please feel free to chime in in the comments.

Bicycling - Safety vs Preference

I came across a great article today on what types of bicycling infrastructure is the most preferred and compares it to what type of infrastructure is the safest.  The studies cited go a little against conventional wisdom.  I really thought the scatter plot chart below was telling and city transportation engineers and DOT's should take note.  

The real surprise to me was that paved multi-use paths were the second most preferred type of infrastructure but they were also the second most dangerous.  

Check out the article for an interesting read.

Dedicated Bike Lanes Can Cut Cycling Injuries in Half - The Atlantic Cities

Eleven Atlanta Area Residents Die in Pre-Fourth of July Crashes, Four Others Injured

Our hearts and prayers go out to those mentioned in the articles below and their families.  Eight of the nine headlines are on AJC.com right now.  These aren’t archived, they are headlines for their respective counties. 

There have been eight traffic related deaths in the metro area in the past few days.  Another three people were injured after a car went down an embankment and just today, powerful storms blew over eight tractor trailers in Henry County.  In a particularly gruesome story that didn’t occur in the metro area but involved a family from Lawrenceville, a mini-van in Miami ran off the road and on to a sidewalk killing three members of the Lawrenceville family as they were leaving a Florida Marlins game.  The fourth member, a ten year-old girl is in stable condition.

If there were any other reason for these deaths, they would be combined into a major news story.  Something like; ‘Eleven Atlanta Area Residents Die in Pre-Fourth of July Crashes, Four Others Injured’  There is a possibility that this will be picked up as a news story sometime this week.  However, that possibility only exists because it is a holiday week that is notoriously dangerous.  Any other week, and there is no way these accidents would be grouped into a larger story about a trend in traffic related deaths.  These types of accidents are so commonplace in our society that we barely blink when we see the headline and often times the story includes details about how long a road or intersection was closed after the crash as if we should be concerned with commute times.

Every time I see a headline like the ones above, I wonder if it might have been prevented had the victim(s) been able to walk, bike or take transit to their destination?  What if we had truly complete neighborhoods where people could choose to walk to to their jobs, bars, stores and parks?  Could we reduce the number of deaths on our roads?  The single most deadly thing we do every day is get behind the wheel of our cars.  Think about it... and be careful out there.

Fire Truck Fire Truck.. Zoom Zoom Zoom...

This has to be the world's smallest fire truck. It looks ridiculous in the setting but could really be useful in areas with narrower streets. Much of the reasoning behind our neighborhood streets being so wide and thus speed inducing is due to the needs of fire and emergency vehicles.

In America, we have an obsession with large equipment that many parts of the world just don't have. This truck is in Ontario and probably serves its purpose for 99% of the emergencies it responds to. It's also a lot cheaper to buy, service and maintain and doesn't require as much asphalt (expensive) to get through a neighborhood.

If the Forsyth FD had one of these, they probably wouldn't have as much of a problem with the narrow streets in Vickery Village. Remember that many more people die in US each year due to high speeds on roads than due to fires in buildings.. just sayin..

ht: Chuck Mahron @ Strong Towns