Trip generation characteristics of discount supermarkets

Institute of Transportation Engineers. ITE Journal, Nov 2003 by Brehmer, Christopher L, Butorac, Marc A

THIS FEATURE PRESENTS THE RESULTS OF A TRIP GENERATION STUDY A 10 DISCOUNT SUPERMARKET FACILITIES OPERATED BY THE SAME COMPANY. THE TRIP RATE AND TRIP TYPE ASSOCIATED WITH THE DISCOUNT SUPERMARKET COMPANY WERE FOUND TO BE LOWER THAN THOSE OF THE STANDARD TRIP GENERATION SUPERMARKET AND DISCOUNT SUPERMARKET LAND USES.

OVER THE PAST SEVERAL YEARS, many grocers have attempted to create a niche market by selling high-quality goods, creating in-store brand names, selling products in bulk and/or selling products at discounted prices. As these trends have continued, building sizes typically have increased and the trip generation profile of grocers has evolved.

Two elements are of particular concern in assessing the transportation impacts and needs of grocers: trip generation and trip type. The trip generation profile of a typical store is important because it is necessary to determine the on-site and off-site transportation impacts associated with that store. Trip type is important both in understanding trip origins and modal split and in enabling better planning of site access and parking to prevent spillover into residential neighborhoods.

This feature provides a summary of a trip generation study prepared for a major discount supermarket company located in the western United States.

CURRENT TRIP GENERATION DATA

The Institute of Transportation Engineers' (ITE) Trip Generation typically is used to estimate the number of site-generated trips associated with a given land use.1 The Trip Generation Handbook is used to determine trip type.2 Both publications include data for two land uses commonly employed to study large grocers: supermarkets (ITE Eand Use Code 850) and discount supermarkets (ITE land Use Code 854).

In addition to these two land uses, data for shopping centers (ITE Land Use Code 820) sometimes are used to evaluate the transportation impact of grocers when they are part of a larger shopping center development.

ITE Land Use Code 850 characterizes supermarkets as typically being "free-standing retail stores selling a complete assortment of food, food preparation and wrapping materials and household cleaning and servicing items. Supermarkets may also contain facilities such as money machines, photo centers, pharmacies and video rental areas."

ITE trip generation data for the supermarket land use represent average store sizes ranging from approximately 27,000 square feet to 53,000 square feet, with most of the data points based on the smaller store sizes.

By comparison, ITE Land Use Code 854 characterizes discount supermarkets as typically being "free-standing retail stores selling a complete assortment of food (often in bulk), food preparation and wrapping materials and household cleaning and servicing items at discounted prices."

The store sizes associated with the ITE discount supermarket database range from less than 10,000 square feet to more than 125,000 square feet. ITE specifically cautions Trip Generation users to employ discount supermarket data carefully because of the small data sample size (daily trip rate data are not available). For this reason, some jurisdictions will not accept trip generation projections based on ITE discount supermarket data, even though the proposed land use may not correlate well with ITE's supermarket definition.

DISCOUNT GROCERS

Currently, a segment of the grocer market is focused on volume delivery of standard grocery products at discounted prices. One of the major grocers on the west coast of the United States follows this business practice while serving customers 24 hours per day and 7 days per week. The stores feature a full line of groceries as well as in-store departments that include a bakery, a pizza shop with made-to-order pizza, quantity bulk foods, a delicatessen, a seafood department, a fresh meat department, a fresh produce department, organic products and a health and beauty aids department.

The stores typically sell the same type and size of brand name products as conventional supermarkets but have the lowest prices of any competitor in the trade area in which they operate. As a result, the stores' annual sales volume far exceeds that of typical supermarkets.

While sales volume is higher than at other supermarkets, it has been hypothesized that actual store trip generation on a square-foot basis is lower due to the comparatively large store size and the higher volume of groceries purchased per customer. Typical modernday supermarkets range in size from 45,000 to 60,000 square feet; the typical supermarket building in the company under study is between 70,000 and 90,000 square feet.

This unique characteristic leads to the perceived need to better identify trip generation, trip characteristics and subsequent transportation impacts associated with existing and future company stores.

DATA COLLECTION

Ten study sites operated by the company were selected for data collection activities. Data collection at the study sites included:

* A traffic count program to obtain weekday p.m. peak-hour trips; 24-hour weekday, Saturday and Sunday trips; and mid-day peak-hour trips on a Saturday.