We continue to innovate within our channel and are able to utilize the most productive of our various Dollar General store formats based on the specific market opportunity. We expect store format innovation to allow us to capture additional growth opportunities within our existing markets. We are now using two larger format stores (approximately 8,500 square feet and 9,500 square feet, respectively), and expect the 8,500 square foot format, along with our existing Dollar General Plus format of a similar size, to become our base prototypes for the majority of new stores, replacing our traditional 7,300 square foot format and higher-cooler count Dollar General Traditional Plus format. The larger formats allow for expanded high-capacity-cooler counts; an extended queue line; and a broader product assortment, including the non-consumable initiative, a larger health and beauty section, and produce in select stores. We continue to incorporate lessons learned from our various store formats and layouts into our existing store base. These lessons contribute to innovation in developing new formats, with a goal of driving increased customer traffic, average transaction amount, same-store sales and overall store productivity.
We have established a position as a low-cost operator, always seeking ways to reduce or control costs that do not affect our customers’ shopping experiences. We plan to continue enhancing this position over time while employing ongoing cost discipline to reduce certain expenses as a percentage of sales. Nonetheless, we seek to maintain flexibility to invest in the business as necessary to enhance our long-term competitiveness and profitability.
We are continuing to deploy “Fast Track”, an initiative aimed at further enhancing our convenience proposition and in-stock position as well as increasing labor efficiencies within our stores. The completed first phase of Fast Track involved sorting process optimization within our non-refrigerated distribution centers, as well as increased shelf-ready packaging, to allow for greater store-level stocking efficiencies, while the ongoing second phase involves adding a self-checkout option, which we plan to have in up to 11,000 stores by the end of 2022. These and the other strategic initiatives discussed above have required and will require us to incur upfront expenses for which there may not be an immediate return in terms of sales or enhanced profitability.
To further optimize our cost structure and facilitate greater operational control within our supply chain, we plan to double the size of our private tractor fleet in 2022. We had more than 950 tractors in our fleet at the end of the first quarter of 2022, and our goal is to have more than 1,400 tractors in the fleet by the end of 2022.
Certain of our operating expenses, such as wage rates and occupancy costs, have continued to increase in recent years, due primarily to market forces, including labor availability, increases in minimum wage rates and increases in property rents. Further federal, state and/or local minimum wage increases could have a material negative impact on our operating expenses, although the magnitude and timing of such impact is uncertain. In addition, we have experienced challenges such as increased costs and disruptions in our business as a result of various global events, including the COVID-19 pandemic and its associated impacts. Such challenges include incremental transportation, distribution, and payroll costs, as well as supply chain disruptions. We continue to experience materially higher supply chain costs and, in some instances, shipping delays, as a result of shipping capacity shortages, port congestion and industry labor shortages. We expect continued inflationary pressures due to higher input costs and higher fuel prices will continue to affect us as well as our vendors and customers, resulting in higher commodity, transportation and other costs, all of which may result in continued pressure to our operating results, and their extent and duration are unknown. To the extent that these inflationary pressures result in a recessionary environment, we may experience adverse effects on our business, results of operations and cash flows. While we expect some challenges to persist, certain of our initiatives and plans are intended to help offset these challenges; however, they are somewhat dependent on the scale and timing of the increased costs, among other factors. There can be no assurance that our mitigation efforts will be successful.
Our diverse teams are a competitive advantage, and we proactively seek ways to continue investing in their development. Our goal is to create an environment that attracts, develops, and retains talented personnel, particularly at the store manager level, because employees who are promoted from within our company generally have longer tenures and are greater contributors to improvements in our financial performance.
To further enhance shareholder returns, we repurchased shares of our common stock and paid quarterly cash dividends in the first quarter of 2022. We expect to continue our share repurchase activity and to pay quarterly cash dividends for the foreseeable future, subject to Board discretion and approval.
We utilize key performance indicators (“KPIs”) in the management of our business. Our KPIs include same-store sales, average sales per square foot, and inventory turnover. Same-store sales are calculated based upon our stores that were open at least 13 full fiscal months and remain open at the end of the reporting period. We include stores that
