Chapter 29.32


29.32.010    Design methods and procedures.

29.32.020    Pavement types.

29.32.030    Design input variables.

29.32.040    Pavement design procedures.

29.32.050    Truck routes.

29.32.010 Design methods and procedures.

The following pavement design methods and procedures shall be followed to create a consistent pavement thickness design throughout the urban area.

This chapter references the truck route map developed for the urban area of the City and County. The truck route map must be consulted prior to beginning pavement design to assure that the design will accommodate anticipated truck loading.

(Res. 39-04 (§ 7.0), 4-21-04)

29.32.020 Pavement types.

Pavement types which may be used for construction of City and County streets include Hot Mix Asphalt (HMA) and Portland Cement Concrete (PCC) pavements. The City and/or County shall approve in advance the type of pavement.

(Res. 39-04 (§ 7.1), 4-21-04)

29.32.030 Design input variables.

Parameters that must be evaluated in order to design an adequate pavement structure include subgrade soil properties, surface and sub-surface drainage, materials properties, environmental factors and traffic loading over the analysis period.

The minimum traffic analysis period to be used for the design of pavements for City streets is 30 years. Traffic growth rates vary depending upon the street classification, zoning location and other variables. Growth rates for most major streets are available from the Mesa County Regional Transportation Planning Organization, phone (970) 244-1830. The minimum growth rate to be used for traffic projections on major streets is 2.2 percent per year.

Traffic distribution by vehicle type shall be determined from actual traffic counts and projections based on land uses and future build-out of area serviced by the road. Classification of vehicles derived from traffic counts are available for most major streets from the City of Grand Junction, Transportation Engineering Division, phone (970) 256-4110.

All other pavement design parameters including 18 kip equivalency factors, lane distribution factors, Resilient Modulus (MR) conversion equations, drainage coefficients, reliability factors and serviceability indices shall be determined in accordance with the Guideline for the Design and Use of Asphalt Pavements for Colorado Roadways, published by the Colorado Asphalt Pavement Association.

(Res. 39-04 (§ 7.2), 4-21-04)

29.32.040 Pavement design procedures.

(a)    Flexible Pavement Design Procedure. Flexible pavement design includes asphalt concrete (AC) surfaces and surface treatments (ST). Flexible pavements shall be designed in accordance with the principles and procedures illustrated in the AASHTO Guide for Design of Pavement Structures (latest edition). The computer software for the AASHTO guide is AASHTOWare DARWin 3.1 Pavement Design and Analysis System.

(b)    Rigid Pavement Design Procedure. Rigid pavement design includes plain jointed (JCP), jointed reinforced (JRCP) and continuously reinforced (CRCO) concrete pavements. Rigid pavements shall be designed in accordance with the principles and procedures illustrated in the AASHTO Guide for Design of Pavement Structures (latest edition). Approved software for design of rigid pavement includes AASHTOWare DARWin 3.1 and WinPAS developed by the American Concrete Pavement Association.

(Res. 39-04 (§ 7.3), 4-21-04)

29.32.050 Truck routes.

Primary and secondary trucks routes are shown on the truck route map.

(Res. 39-04 (§ 7.4), 4-21-04)

Truck Route Map (PDF)