5 - Alternative Surface Treatments for Dirt or Gravel Residential Alleys
C I T Y O F B O U L D E R
TRANSPORTATION ADVISORY BOARD
NON-AGENDA ITEM
MEETING DATE:
November 1, 2004
AGENDA TITLE:
Alternative Surface Treatments for Dirt or Gravel Residential Alleys
PRESENTER/S:
Tracy Winfree, Director of Public Works for Transportation
Felix Gallo, Coordinator for Transportation & Utilities Maintenance
EXECUTIVE SUMMARY:
There are currently approximately 70 dirt or gravel public alleys in the city, which represent about 18
SHUFHQWRIDOOWKHFLW\¶VSXEOLFDOOH\V$OOH\VSURYLGHYHKLFOHELNHDQGSHGHVWULDQFRQQHFWLRQV
between cross streets, access to commercial and residential properties, access for trash collection and
location of public and private utilities. Alleys are treated similarly to streets, with the fundamental
principles that govern pavement maintenance practices as follows:
Most alleys are public rights-of-way, and as such they are owned by the city and are for the
benefit of all users. Decisions on the type of surface and the maintenance of the alleys is
GHWHUPLQHGE\ZKDWLVEHVWIRUWKHFRPPXQLW\DQGWKHFLW\¶VLQIUDVWUXFWXUHDVDZKROH
The surface treatment chosen, or allowed, must be reasonably rideable for all users;
The surface treatment selected should be cost-effective. The cost to install a surface
treatment, and its associated ongoing maintenance, need to be proportional to the functional
needs of an area and to the life span of the treatment; and,
0DLQWHQDQFHLVSHUIRUPHGWRSURWHFWWKHFLW\¶VH[LVWLQJFDSLWDOLQYHVWPHQWLQLWVDOOH\V7KH
objective of alley maintenance is to keep the surface LQDVQHDUWR³DVEXLOW´FRQGLWLRQDV
SRVVLEOHLQDQHIIRUWWRUHGXFHRUHOLPLQDWHWKHFLW\¶VOLDELOLW\H[SRVXUH0DLQWHQDQFH
practices focus on preventive maintenance and bringing alleys up to acceptable maintenance
standards.
The typical maintenance that is performed on dirt or gravel alley is a biannual grading and reshaping of
the alleys as needed. Unpaved surfaces are more subject to weather elements and wear and tear than
paved surfaces and can deteriorate more rapidly.
The city does upgrade alleys - converting from dirt and gravel to recycled asphalt (asphalt pavement
WKDWLVJURXQGXSLQFRQMXQFWLRQZLWKWKH\HDUO\VWUHHWRYHUOD\SURJUDP
RUDVSKDOWRYHUOD\±ZKHQDQ
alley experiences ongoing maintenance problems and/or has drainage issues.
Paving an alley in asphalt provides a hard surface and has many advantages over dirt, gravel or
recycled asphalt surfaces. Asphalt helps move water to where it needs to go, unlike dirt and gravel
which absorbs and holds water within the material and which then forms mud, holes and depressions.
1
Over the years, many of the alleys in the downtown/commercial areas have been reconstructed in
concrete. These alley paving projects are funded through the Transportation Capital Improvements
Program (CIP) and involve significant property owner input, coordination and contribution. These
projects typically include overhead utility line burial, combined trash dumpster locations and
enclosures, and complete concrete reconstruction with brick bordering.
Staff has examined other types of materials such as crushed concrete, structural pavers, granite chips,
and combination surface treatments such as concrete and turf paths. Staff is always willing to
consider alternative materials as long as the material is suitable for the projected traffic use of the
alley and that the material abides by the design standards in effect.
Fiscal Impacts:
Budgetary:
None, if alleys are not improved from dirt / gravel construction. Improvement from a dirt
/ gravel alley to a recycled asphalt alley also will not have a budgetary impact as the
recycled asphalt material is surplus from city CIP projects. Upgrading to a paved asphalt
alley would have a budgetary impact and would have to be programmed in to the
operating budget year. The cost is dependent on the size of the alley as well as expected
traffic volume. Alleys requested to be paved or upgraded by the adjacent property
owners and not identified as needing paving at the time would be paid for on a 50/50 split
with the city and the adjacent property owners.
Given the low traffic volume on residential alleys and the slight impact to the general
public, upgrading alleys is not a high priority when compared to the rest of the
transportation system. And, also given the current and forecasted financial constraints, it
is not likely that funding for such improvements will occur in the near future unless it is a
matter of public safety.
In the event that funds are available in the future, the existing proposed material(s) and
process outlined in this document will be used as a basis for alley maintenance decisions.
Staff Time:
Grading of dirt/gravel alleys and/or upgrading to a recycled asphalt alley would be part of
the normal work plan as would paving an alley if identified as requiring this surface
treatment. Alleys requesting additional work or improvement by the adjacent property
owners would have to be programmed in during the year.
Other Impacts:
Environmental:
Travel on dirt and gravel alleys kicks up dust and contributes to PM10 particulate matter
pollutionAn unimproved dirt/gravel alley will also contribute to turbidity in the
.
receiving drainage ways as a result of erosion and off-site tracking during storm events.
NPDES Phase II regulations require the city to adopt best management practices
regarding sediment and storm water runoff.
Other Board and Commission feedback:
Paving of alleys not currently paved in historic districts requires prior approval in the form of a
landmark alteration certificate. Landmark alteration certificates can be issued by the landmarks
design review committee --a subcommittee of the Landmarks Preservation Advisory Board, and one
member of Planning staff. However, proposals that would have a significant impact to the character
of the district are referred to the full Landmarks Board for a public hearing. Since alleys are a strong
2
visual element of a district, and changes to them garner substantial public interest, alterations to them
are typically referred to the full Board for a public hearing. In determining whether paving would be
considered appropriate, the Board has referred to the following guidelines from the Mapleton Hill
Design Guidelines:
Efforts should be made to maintain the character of the alleys in the District. (Guideline
D.5);
The Boulder Revised Code [Section 9-3-3.14, BRC, 1981] requires paving of alleys in certain
circumstances in the HZ-E zoning district. A Landmark Alteration Certificate is required for
paving within the district, even when required by City Code. (D.6);
A permeable, soft-edged surface may be a solution to control drainage and dust and should
.
be used as an alternative to hard, non-porous paving, when not otherwise prohibited by City
Codes. (D.7);
In the case that paving is determined to be necessary, a paving material that preserves the
utilitarian character of the alley will be appropriate. (D.8); and,
Consistent with the needs of public health, safety, and welfare and the considerations of cost,
any public improvements in the District should maintain and reinforce the historic character
of the District. (W.)
Thus far, the Board has approved resurfacing of two alleys with recycled asphalt (1992 and 1994),
but has denied an application for paving of an alley with hot/ full-depth asphalt (1999).
From a maintenance and safety perspective, asphalt is often the most desirable surface, particularly
on alleys that are heavily traveled; however, this surface has been denied in the past on alleys in
historic districts.
Public feedback:
The current procedure and process for determining surface treatment upgrades for alleys is based on the
decision (or vote) of those property owners immediately impacted by the improvement. If property
owners abutting an alley want to have recycled asphalt or an asphalt overlay upgrade, they must go
through a petition process and gather majority support from property owners abutting the alley to have the
upgrade installed. If an asphalt overlay is supported by the property owners of an alley, then these owners
must split the cost of the upgrade 50/50 with the city.
optional
:KHQDSURMHFWLV³´ QRWUHTXLUHGE\DPDLQWHQDQFHRUWUDQVSRUWDWLRQQHHG
WKH%RXOGHU
Revised Code (BRC) provides guidelines for what isDQ³DIIHFWHGSURSHUW\´±LQRWKHUZRUGVZKR
is impacted by or benefits from an improvement. For alleys, the standard or measurement is based
on those properties directly adjacent. This is because alleys primarily function to provide
access to the rear or side of abutting lots or buildings (homes and garages).
When a project is not optional, i.e., there is a maintenance requirement to make a repair or
improve an alley (and the alley is rated in fair to poor condition), then Transportation
Maintenance staff notifies the adjacent property owners of the proposed work.
Staff reviews all petition requests for optional upgrade requests and if it does not feel that an alley needs
an upgrade of surface treatment it will notify the requesting property owners that the work will not be
considered/done.
In general the public has been receptive to the improvement of an alley from dirt/gravel to
recycled asphalt or pavement. The number of complaints received from an alley regarding
maintenance has significantly dropped off as has the maintenance requirements observed by
staff.
3
Staff recommendation:
Staff recommends that problematic alleys be upgraded to a minimum recycled asphalt surface.
This type of upgrade will decrease the amount of time involved in the maintenance of a
problematic alley, improve rideability, and lower the amount of dust emissions as compared to a
dirt or gravel alley. A recycled asphalt or paved alley surface will also decrease the amount of
sediment that enters the storm water system when compared to a dirt or gravel alley. However,
if abutting property owners are adverse to a proposed upgrade staff will work with the property
owners to try find an appropriate resolution.
Analysis:
N/A
Matrix of options:
N/A
Attachments:
N/A
4
5