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Dead end maximum length?

Streck

Cyburbian
Messages
605
Points
18
Our zoning ordinance started out having 500 feet for the maximum length for a dead end street. It has gradually increased to 600 and then 700 feet. Is there a planning reason that a dead end street should not exceed a certain length? If so, what is it?

If a street forks, is the dead end measured from the fork, or from the point where there you actually have two or more ways to exit the area?

If a subdivision has only one entrance/exit and no internal loop road, is that considered a dead end for length purposes?

Is water pressure on a dead end water line or fire line a factor?

Is turn-around time for a fire truck on a run a factor?

Is the number of houses on a dead end (one way out) street a factor?

If a tree falls and blocks the dead end road, is there an acceptable number of houses that statistically can be figured to go without access without city liability for poor planning?

Is 300 feet the maximum length that a young child could be expected to walk to a school bus pick up point, so that the school bus would not have to enter the dead end street?

Email appreciated.

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Messages
3,690
Points
27
Our department discourages cul-de-sacs for a number of reasons. Primarily, from a planning standpoint, dead end streets do not promote healthy traffic circulation, as well as the many public safety concerns.

New subdivisions are required to provide stub out streets to connect in the future to adjacent undeveloped properties, or to utilize the existing stub out connections in previously developed adjacent properties.
 

Chet

Cyburbian Emeritus
Messages
10,624
Points
34
Alot depends on local preference, and the size of your Fire Chiefs... well never mind. I'll say truck.

Our local codes allow them to be 1200 feet, but the comprehensive plan states as a matter of policy there should be no more than 40 homes served by these arrangements. There is no statistical validity to that number that I can find.

We measure the distance from the point of 2 accesses, not necessarily the last fork.

Loop roads are considered dead ends, and our 1200 foot rule applies only to the loop.

We always loop water mains to avoid pressure problems.

Turning radii for emergency vehicles is a factor in designing the street's terminus.

Our school district drops kids much farther than 300 feet from their doorstep on rare occassion. We are in an area with very high service expectations, so drops are practically on their door step.

Good luck.
 

seannelson

Member
Messages
39
Points
2
I work for a rural county, and we have a 600' maximum cul de sac road distance permitted by code. I am currently dealing with this issue as it pertains to multiple cases. In a recent industrial plat we permitted a platted private cul de sac street that exceeds the 600' provision, but prior any construction of the road beyond 600' a secondary access (part of the plat) must be created allow emergency response vehicles another means of access.
 

Jeff

Cyburbian
Messages
4,161
Points
27
1200' is usually the length I've seen but can't tell you why. It's not a fiure truck thing though (volunteer fireman on da side). An engine (fire truck) boosts the water pressure it is receiving to a desired pressure, rural communities frequently draw water out of ponds (called drafting). Turning around? Do you really think an extra 500' makes a difference in response time...nah. I'd be willing to be that most drivers could make the K-turn faster in an engine than you could in your car also.

You also need to consider the grade of the road and whether storm sewer is provided or not, if the road is curbed etc. For example, you don't want all the runoff hitting the last house.

If the houses on the road are to be sewered they will most likely use gravity. If the house is at the end of the road is the high point, the turds will be flying by the time they hit the manhole at your intersection. If it is the low point, there is a significant amount of earthwork required in order to install sewer, so there is a cost issue also.


All I can think of right now.
 

PlacesForPeople

Cyburbian
Messages
29
Points
2
We do have language prohibiting cul-de-sacs, as a measure to promote better connectivity of the street network. I thought there was language specifying maximum length, but can't find it right now. Currently reviewing a subdivision that has skirted the issue of cul-de-sacs (or are attempting to) by providing "urban open space" in the center of the turnaround. However, connected roads are entirely feasible for the site, so staff does not support.

Also reviewing a subdivision the developers would like to be a gated community (Million dollar, exclusive homes), but we don't allow private streets or blockage of public streets, so they are pretty hot about it but keep submitting plans. (all lots MUST front on public street) The most recent submittal does not address previous staff comment requesting a stub at one boundary, which might kill the project when it goes to PB.

We also have requirements for maximum block lengths, to promote pedestrian accessibility. these maximum block lengths may be exceeded only if a pedestrian cut-through is provided.

Excerpted from Zoning Ordinance:

In summary, streets shall:
1. Interconnect within a development and with adjoining development. Culs-de-sac shall be allowed only where topographical and/or lot line configurations offer no practical alternatives for connections or through traffic. Street stubs shall be provided within development adjacent to open land to provide for future connections.

5. Be public. Private streets are not permitted within any new development.

Street blocks defined by public streets are the fundamental design elements of traditional neighborhoods. In urban conditions, any dimension of a block may range from 250 to 500 linear feet between cross streets. In major subdivisions the dimension of blocks may not exceed 800 linear feet between cross streets. Within large-lot subdivisions the blocks may be up to 1500 feet. The block pattern should continue to establish the development pattern at the project edge.


Happy Holidays!
 
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