2001 Visible Litter Study
Every year, thousands of tons of litter collect on Texas roadsides. Beginning in the fall of 2000, NuStats, in cooperation with Tuerff-Davis EnviroMedia and the Texas Department of Transportation (TxDOT), conducted a litter survey to better understand the amounts and types of litter that are deposited on Texas roadways. The survey involved collecting litter data from 125 research segments across the Lone Star State, each consisting of a 500- or 1,500-foot stretch of TxDOT-maintained roadway.
Annual Litter Estimates
The results of the 2001 Texas litter survey indicate that approximately 1,033,000,000 items accumulate annually on the nearly 1.1 million acres of the state-maintained highway system (comprised of Interstate Highways, US Highways, State Highways and Farm-to-Market roads). This roughly equates to 465,000 cubic yards or 21,000 tons of litter.
On a mile per mile basis, the largest amount of litter accumulates on the Interstate Highway system (2,500 items per month per mile), followed by State Highways (1,900 items per month per mile), US Highways (1,000 items per month per mile), and finally Farm-to-Market Roads (900 items per month per mile)
Overall, there has been a fifty-two percent (52%) reduction in litter on the state-maintained highway system since 1995.
Physical Composition Analysis
Nearly 20,000 items of litter were collected, analyzed, and classified by their physical composition. Three types of litter comprise more than 90 percent of all litter collected.
Almost half (49%) of all items were made of paper and paperboard. These items ranged from paper grocery bags to miscellaneous pieces of cardboard.
Thirty percent (30%) of collected items were plastic, making this the second most common type of litter.
Fourteen percent (14%) of the items were classified as metal items.
The remaining litter was comprised of glass, textiles, rubber/leather, and wood.
Litter Use Analysis
Analyzing litter by its use provides insight on how and why litter might be generated in the first place. The collected litter was categorized into ten separate broad litter use categories. Three categories comprise nearly two-thirds of all litter collected.
One out of every five items of litter (20%) was food-related litter. Items in this category include fast food trays, food wrap, food utensils, beverage cups, ice bags, and condiment packs.
Household/personal items (household-generated litter such as grocery bags, paper towels, tissues, etc.) and tobacco-related items (cigarette butts, snuff cans, chewing tobacco pouches, etc.) each accounted for 19 percent of litter collected.
The remaining seven litter use categories, in descending order, included non-alcoholic beverage litter, alcoholic beverage litter, construction/industrial litter, printed material litter, other litter, automotive litter, and agriculture/garden litter.
Litter Item Analysis
Over 99 percent of litter collected was identifiable.The most common litter item found on Texas roadways was the cigarette butt, which comprised 14 percent of all identifiable litter. In 1995, this litter item made up 48 percent of all identifiable litter, representing a substantial reduction.
Other litter items frequently found during the 2001 litter survey were cardboard pieces (12%), food wrap (9%), beer cans (6%), beverage cups (6%), tissues and paper towels (5%), cigarette packs (4%), and soda cans (4%).
Brand Name Analysis
Approximately 56 percent of all litter collected was identifiable by brand name. Brand name cigarettes accounted for approximately one-fourth (24%) of all identifiable brand names. Fifteen percent of all brand name cigarettes were Marlboro (12%) and Marlboro Light (3%). Doral (4%), Salem (3%) and Newport (2%) were the next most prominent litter brand names.
Other often-found brand names included Bud Light (3%), Coca-Cola Classic (3%), Texas Lottery (3%), Dr. Pepper (3%), Budweiser (3%) and McDonald’s (3%).
Influences of Litter Amounts
In addition to creating statewide litter estimates and analyzing the types of litter found on Texas roadways, the 2001 litter survey sought to uncover variables that potentially affect the amounts of litter that accumulate on the state-maintained roadway network.
Traffic volume is the single most significant factor that influences the amount of litter on Texas roadways.
Previous litter studies have shown that roads that are heavily traveled are “dirtier” than less traveled roads?increased traffic equals increased litter. The 2001 Texas litter survey results support these previous findings.
Sources of Litter
Establishments such as convenience stores, fast food restaurants, and gas stations represent potential litter sources. The presence of these facilities may increase or decrease the amount of litter that is found on roadways within close proximity of them.
The major findings related to proximity of litter sources and litter volume are:
As the number of these potential litter sources increase, so do the amounts of roadside litter.
A statistically significant relationship between litter amounts and the proximity of fast food restaurants, liquor stores, parks, rest stops, and shopping malls was measured on at least one research segment.