(a) When the provisions of Section 901.35 (Function and Hierarchy) specifically provide for certain streets to be planned and design based on expected average daily traffic (ADT) levels, the computation of said traffic levels shall be in accordance with the requirements and restrictions set forth herein. The trip generation standards set forth herein are based on nationally accepted standards and shall receive specific attention during the annual regulation review required by Section 900.15.
(b) The use of this method of performance based street design is elective on the part of the developer. When the developer elects not to utilize this method, or the ADT levels for the proposed streets cannot be adequately determined, then the proposed streets shall be planned and designed in accordance with the "General" street standards of Section 901.61 (Minimum Street Standards) based on the function of the proposed streets.
(c) This method of design may be used when all of the following criterion can be met:
(1) These standards are applicable only to residential streets and do not apply to streets serving commercial or industrial properties.
(2) The streets and lots, or building sites, must be designed so as to define all dwelling units to be served and to preclude future construction of additional dwelling units which are not included in the ADT calculations.
(3) The street layout must be designed so as not to encourage through traffic from other areas which are not included in the ADT calculations.
(d) The expected average daily traffic level for a street, or series of streets, shall be determined based on the expected number of daily trips generated by all dwelling units served by said street, or streets. The expected number of daily trips, to and from a dwelling unit, for various types of dwellings shall be as follows:
TRIP GENERATION STANDARDS | |
HOUSING TYPE | AVERAGE WEEKDAY TRIP GENERATION RATE |
Single family-detached | 10.0 Trips/D.U.* |
Single family-attached** | 8.1 Trips/D.U. |
Apartment building*** | 6.1 Trips/D.U. |
Mobile home park | 5.0 Trips/D.U. |
Retirement community | 3.3 Trips/D.U. |
* Trips per dwelling unit.
** Includes duplexes, townhouses, and similar multiple-single family dwellings where each dwelling unit has its own separate entrance.
*** Includes any building, having three or more dwelling units, where dwelling units share a common entrance. When a particular type of dwelling is not specifically listed, then the listed type which it most closely resembles shall be used.
(e) Computation of ADT. A dwelling unit is deemed to contribute traffic to a particular street if the driveway serving the dwelling intersects with said street. Should a dwelling have a driveway which intersects two different streets then the traffic generated on each street shall be one-half (½) of the total trips generated by the dwelling.
(1) The total trips generated by each type of dwelling on a subject street shall be calculated by multiplying the total number of dwelling units of each type times the appropriate trip generation rate.
(2) The total trips generated on a subject street shall be the sum of the trip totals for each type of dwelling on said street plus the sum of the ADT levels for all other streets which intersect with the subject street.
(3) The ADT for the subject street shall be established at its first point of intersection with another street, or streets, of equal or higher order in the street hierarchy. When a street qualifies as a through street the ADT at each intersection shall be one-half (½) of the total trips generated on the subject street. When a street qualifies as a dead-end then the ADT at the intersection which provides access to a higher order street shall be the total trips generated on the subject street; should another intersection exist its ADT value shall be zero (0).
(4) The calculated ADT levels for each street, at its intersection with another street or equal or higher order, shall be within the applicable ADT range limits (see Section 901.61 (Minimum Street Standards), for the subject street function (local residential access, residential subcollector, etc.).
(Ord. 1327. Passed 5-9-91.)