Engineering Subcommittee

Alternatives Evaluation

September 27, 2005

 

Pavement Evaluation

According to Reitz, and Jens, Inc. (R&J) Pavement and Drainage Evaluation, December 10, 2004:

§    University Hills pavement consists of layers of chip seal (gravel with an asphalt binder) over a crushed rock base.

§    The combination of pavement thickness, composition, and materials and the soil subgrade types are generally suitable for a light residential street pavement.

§    Existing pavement throughout the subdivision is exhibiting fatigue failure.

§    Thin wearing surfaces are being overloaded by vehicle turning forces at intersections.

§    Wheel track rutting was observed in many areas.

§    Pavement degradation will continue, if not accelerate, with time.

§    There are no interim measures, other than spot repairs of known problem areas, that will prolong the life of the streets.

 

Pavement inspection was performed by the Engineering Subcommittee and municipal pavement engineers known to the subcommittee.  The consensus opinion of these engineering professionals was that the streets were not in the state of imminent failure suggested by R&J.  Furthermore, it was their consensus opinion that that the life of the streets could indeed be prolonged through spot repair and ongoing maintenance. Recommended maintenance included periodic application of chip-seal, repair of areas of localized pavement or subbase failure, and repair of curb and gutter and gutter/pavement interface to minimize moisture intrusion into the subbase.

 

The subcommittee met with R&J project and management personnel on April 26, 2005.  The subcommittee voiced its belief that R&J had overstated its concerns regarding pavement condition and life.  Mr. Reitz stated that their recommendation would minimize street maintenance costs.  Mr. Reitz further stated that a good maintenance program, including periodic applications of chip-seal would extend the pavement life for some time.  Mr. Reitz’s responses confirmed the subcommittee’s opinion that street life could be significantly prolonged through periodic maintenance and repair.

 

Stormwater Inlets and Piping

Discussions with the Metropolitan St. Louis Sewer District (MSD) suggest that MSD will repair existing stormwater inlets as needed and install new inlets and associated subsurface piping where appropriate.  Costs are not included in Alternatives 2, 3, and 4.

 

MSD has prepared bid packages for performing inlet repairs.  They are awaiting internal approval. Our MSD contact suggests that approval is a formality and hopes to solicit bids and award most of the work by January, 2006.   Planning for the installation of new inlets has not begun.  We will remain in contact with MSD to track and support performance of this work.  The cost of each alternative will increase by approximately $75,000 if the cost of this work must be borne by University Hills.

 

Driveway Aprons

Reitz and Jens estimated that approximately 20% of driveway aprons were deteriorated and in need of replacement.  Although a specific inventory and evaluation was not performed, the subcommittee believes that less than 20% of the aprons are nonfunctional.

 

The trustees have indicated that they have replaced aprons on a case-by-case basis.  The Subcommittee generally recommends that the Trustees continue this practice.  Where that portion of the apron that comprises the gutter is significantly cracked and broken, that portion should be saw-cut and replaced as part of the curb and gutter replacement program.

 

Whether or not a car “bottoms out” on a driveway apron may have as much to do with the vehicle or the street grade as with the apron.  It is unlikely that many apron alignments have changed significantly since properties were purchased.  Realignment of an apron to eliminate “bottoming” while maintaining adequate drainage will be far more difficult and expensive than like-for-like replacement of broken or crumbling concrete.  We recommend that the trustees continue the practice of replacing aprons on a case-by-case basis. 

 

SUMMARY OF ALTERNATIVES

1. No Action.  This alternative does no replacement or repair of curb, gutters, and streets beyond minimal maintenance and repair.

 

Pros	Cons
Minimum initial cost.	Replaces nonfunctional curb and gutter and repairs streets at the discretion of trustees as normal assessments allow.
	Delay while capital improvement fund accumulates may lead to additional deterioration and associated repair costs.
	Neighborhood curb and gutter will not have uniform appearance.

 

2. Functional (21%) C&G Replacement.  This alternative replaces curb and gutter that is significantly damaged or nonfunctional. This alternative replaces approximately 21% of the curb and gutter and repairs approximately 15% of the pavement/gutter interface.  This alternative performs selected pavement repair (Kingsbury), provides two applications of chip-seal, and performs pavement repair as needed.

 

Pros	Cons
Replaces all nonfunctional curb and gutter.	Neighborhood curb and gutter will not have uniform appearance.
Extends pavement life.
Repairs streets as needed.

 

3. Functional (37%)  C&G Replacement.  This alternative replaces all curb and gutter with more than minor cracking.  This alternative replaces approximately 37% of the curb and gutter and repairs approximately 15% of the pavement/gutter interface.  This alternative, performs selected pavement repair (Kingsbury), provides two applications of chip-seal, and performs pavement repair as needed.

 

Pros	Cons
Replaces all nonfunctional curb and gutter.	Replaces functional curb and gutter with cosmetic flaws.
Replaces curb and gutter with more than minor cracking.	Neighborhood curb and gutter will not have uniform appearance.
Extends pavement life.
Repairs streets as needed.

 

4. Complete C&G Replacement.  This alternative replaces 100% of the curb and gutter and repairs 100 % of the pavement/gutter interface.  This alternative performs selected pavement repair (Kingsbury), provides two applications of chip-seal, and performs pavement repair as needed.  Note that curb and gutter that has been installed recently will not be replaced.

 

Pros	Cons
Replaces 100% curb and gutter.	Replaces functional curb and gutter with cosmetic or no flaws.
Provides uniform curb and gutter appearance.
Repairs all interface.
Extends pavement life
Repairs streets as needed.

 

5. R&J Recommendation.  The Reitz and Jens alternative replaces 100% of the curb, gutter, and streets, repairs certain existing stormwater inlets and provides new inlets as appropriate.  This alternative does not provide for routine maintenance of curb, gutter, or streets after installation.   

 

Pros	Cons
Replaces 100% of curb and gutter.	Streets are not in state of imminent failure.
Replaces 100% of Streets.	Replaces functional curb and gutter with cosmetic or no flaws.
Minimizes future curb, gutter, and maintenance costs.	Maximum disruption during construction.
Uniform curb and gutter appearance.	No ongoing maintenance and repair.
Uniform street surface.	High cost.

 

6. U City Standard.  This alternative will bring the streets, curb, and gutter up to University Standards. It replaces 100% of the curb, gutter, and streets, repairs certain existing stormwater inlets and provides new inlets as appropriate.  This alternative will widen Teasdale, Creveling, Bedford, Stratford, Norwood, Purdue, Warren, and Midvale Avenues by approximately four feet and will require removal and replacement of 300 trees and 10% of the sidewalks.  This alternative does not provide for routine maintenance of curb, gutter, or streets after installation.  There is no value added with this alternative if the subdivision will remain private.

 

Pros	Cons
Replaces 100% of curb and gutter.	Streets are not in state of imminent failure.
Replaces 100% of Streets.	Replaces functional curb and gutter with cosmetic or no flaws.
Minimizes future curb, gutter, and maintenance costs.	Maximum disruption during construction.
Uniform curb and gutter appearance.	Loss of 300 mature trees on widened streets
Uniform street surface.	No ongoing maintenance and repair.
Streets suitable for assumption by U City.	No value added if subdivision remains private.
	High cost.

 

COST SUMMARY

The estimated cost of each alternative is summarized below.  Please be aware that these are estimates only, in spite of the accuracy implied by spreadsheet-generated values with six significant figures.

 

Alternative	Total ($) (See Note 3)	Per Residence ($) (See Note 2)
1. No Action	(See Note 1)	(See Note 1)
2. Functional (21%) C&G Replacement	609,146	2,446
3. Functional (37%) C&G Replacement	825,613	3,316
4. Complete C&G Replacement	999,272	4,013
5. Reitz & Jens	3,300,000	13,253
6. U City Standard	3,710,000	14,900

Notes:  1. No Action alternatives were not specifically estimated, but may approach or exceed Functional C&G Replacement costs.

2. Average.  No use of annual assessment or capital improvement fund is assumed.  Partial funding through annual assessment and capital improvement fund will reduce per resident cost.

3. Additional Cost if Inlet Repair and New Inlets are not provided by MSD = $75,000.