Table 4-52. Highway Noise Barrier Construction (Miles)
Table 4-52. Highway Noise Barrier Construction (Miles)
| Unknown | R1970-79 | R1980-89 | R1990 | R1995 | 1996 | 1997 | 1998 | Total 1970-98 | |
|---|---|---|---|---|---|---|---|---|---|
| Type I barriersa | 6d | 102 | 419 | 44 | 87 | 34 | 47 | 114 | 1,146 |
| Type II barriersb | 0 | 70 | 128 | 19 | 32 | 15 | 31 | 22 | 391 |
| All other typesc | N | 2 | 28 | 0 | 6 | 0 | 1 | 1 | 79 |
| Total length | 6 | 175 | 575 | 63 | 125 | 49 | 78 | 137 | 1,623 |
| Cost (1998 $ millions) | N | 134 | 656 | 89 | 152 | 60 | 111 | 169 | 1,931 |
a A Type I barrier is built on a highway project to construct a new highway or to physically alter an
existing highway.
b A Type II barrier is built to abate noise along an existing highway (often referred to as retrofit abatement)
and is not mandatory.
c All other types of barriers are nonfederally funded.
d Have not been assigned a year of construction or a cost.
KEY: N = data do not exist; R = revised.
NOTES: Miles have been converted from kilometers. Totals may not match the sum of yearly estimates due to rounding and converting from metric. 24 miles of barriers, while assigned a year of construction, cannot be assigned a cost. Data are produced on a 3-year cycle.
SOURCE: U.S. Department of Transportation, Federal Highway Administration, Office of Environment and Planning, HighwayTraffic Noise Barrier Construction Trends (Washington, DC: 2000), tables 1 and 3.