Chapter 20.30


20.30.010    Purpose.

20.30.020    Applicability.

20.30.030    Organization and content.

20.30.010 Purpose.

It is the purpose of this chapter to outline the minimum content of a traffic impact analysis. A traffic impact analysis responds to a wide variety of issues, varying with the type of development, location of the proposed project, and existing traffic patterns. There are a number of issues that are incorporated into a traffic impact analysis to ensure an efficient and comprehensive review of the impacts associated with a development proposal. (Ord. TLS 97-10-71B Exh. H (part))

20.30.020 Applicability.

A.    A traffic impact analysis shall be submitted with a development permit application when it is determined by the county engineer that a development meets any of the following:

1.    Generates twenty peak hourly trips or two hundred average daily trips;

2.    Significantly affects or exceeds the current or projected level of service of the roadway system adjacent to the development; or

3.    The proposal would affect existing traffic problems in the local area of the project such as an area with a high accident ratio, confusing intersection, or other problems identified by the county engineer; or

4.    A traffic impact analysis may also be required by the county engineer or the director when it is determined that a development proposal may significantly impact adjacent areas, or in the discharge of their responsibilities in the administration of DCC Chapter 19.04.

B.    Traffic impact analyses shall be prepared by a qualified engineer approved by the county engineer. (Ord. TLS 97-10-71B Exh. H (part))

20.30.030 Organization and content.

A traffic impact analysis shall contain the following information:

A.    Introduction and Summary.

1.    Purpose of report and study objectives;

2.    Executive summary:

a.    Site location and study area,

b.    Development description,

c.    Principal findings,

d.    Conclusions,

e.    Recommendations and proposed mitigation measures.

B.    Proposed development and summary of the development proposal, including the following:

1.    Land use and intensity;

2.    Location;

3.    Site plan;

4.    Zoning;

5.    Phasing and timing.

C.    Area conditions including the following:

1.    Study area:

a.    Area of influence;

b.    Area of significant traffic impact.

2.    Study area and land use:

a.    Existing land uses;

b.    Existing zoning;

c.    Anticipated future development.

3.    Site accessibility:

a.    Existing and future area roadway system;

b.    Traffic volumes and conditions;

c.    Transit service;

d.    Existing relevant transportation system management programs;

e.    Other issues as determined by the county engineer and director.

D.    Projected Traffic.

1.    Site traffic for each horizon year:

a.    Trip generation;

b.    Trip distribution;

c.    Modal split;

d.    Trip assignment.

2.    Through traffic (each horizon year):

a.    Method of projection;

b.    Nonsite traffic in study area including the method of projections, trip generation, trip distribution, modal split, and trip assignment;

c.    Through traffic;

d.    Estimated volumes.

3.    Total traffic (each horizon year).

E.    Traffic analysis including the following:

1.    Site access;

2.    Capacity and level of service;

3.    Traffic safety;

4.    Traffic signals;

5.    Site circulation and parking.

F.    Improvement Analysis.

1.    Improvements to accommodate base traffic;

2.    Additional improvements to accommodate site traffic;

3.    Alternative improvements;

4.    Status of improvements already funded, programmed, or planned;

5.    Evaluation.

G.    Findings.

1.    Site accessibility;

2.    Traffic impacts;

3.    Need for any improvements and financing plan;

4.    Compliance with applicable codes.

H.    Recommendations and Proposed Mitigation.

1.    Site access/circulation plan;

2.    Roadway improvements including on-site, off-site and a phasing plan when appropriate;

3.    Transportation system management actions including off-site, on-site and operational.

I.    Conclusions. (Ord. TLS 97-10-71B Exh. H (part))