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The studied-bridge.is located within the US 601-Nc 49 interchange. So~th of the bridge, US 601 has a 22-foot pavement with 8-foot shoulders. In the commercial area north.of the bridge, four travel lanes (two thru plus two turning) are separated ~y a raised concrete medan. Vertical alignment is generally flat. Horizontal alignment is tangent except for a 4-degree curve which begins about 200.feet south of the bridge. Development north 6f the bridge is a mixture of commer- cial and residential. South of the bridge, development is low-density residential. Speed limit is 45 M~H. The currentltraffic volume of 12,300 UPD on US 601 (see Figure 5) is expected to increase to approximately 24,300 VPD by the year 2005. The projected volume includes 6% truck-tractor semi-trailers (TTST) and 5~ dual-tired vehicles (DTT). The'existing bridge (see Figure 3), constructed in 1952, consists of reinf6rced concrete deck girders supported by a reinforced concrete substructure. Overall length is ~15 feet. Clear roadway width is 28.2 feet. The posted weight limit is 26 tons for single vehicles and 33 tons for trucks with trailers. The existing bridge provides~14.0 feet of vertical clearance over NC 49, which has a 24-foot pavement with 8-foot shoulders (see Figure 3). Underneath the str~cture, a horizontal clearance of 40 feet (between piers) is provided. The current traffic volume of 9,500 VPD on. NC 49 is expected to increase to approximately 18,800 VPD by the year 2005. Bridge No. 92 has a sufficiency rating of 47.8 compared to a rating of 100 for a new structure. Several accidents were reported in the vicinity of the bridge from January, 1981 ~ November, 1984. Five accidents occurred on US 601 at the ramp terminals north of the bridge. Two occurred at the ramp terminals south of the bridge. The bridge was struck four times by vehicles traveling underneath on NC 49. Three Of these accidents resulted from inadequate vertical clearance. The other resulted from inadequate horizontal clearance. III. Alternatives Four alternative methods of replacing Bridge No. 92 were studied as follows: