Sub-Standard, Bumpy, Tight, 'Hell Of A Curve'

Glenwood Baker, the state's district traffic engineer for the Ann Arbor area, refers to the "sub-standard degree of curvature" on it. Harold Sherman, a research associate at the University's Highway Safety Research Institute, compared it to "taking off from a ski jump," for certain vehicles. Cpl. Arthur Hughes of the Ann Arbor Pólice Traffic Bureau say it's not really a dangerous curve, but "needs some engineering." And Washtenaw County Sheriff Douglas Harvey, who nearly lost his life there last month, calis it simply "one heil of a curve." The "it" in question is the 1-94 expressway at Jackson Ave. on the west edge of the city, the point at which many a motor vehicle has gone on to that Great Junkyard In The Sky after failing to negotiate the overpass' often - treacherous curve. U n 1 i k e those of Raquel Welch, the curves on this major east-west freeway are neither lovely to behold nor gentle to the touch at Jackson. Rather, they are bumpy, overly "tight" and slippery and especially hazardous when wet or icy. No matter what different reasons are given for the existance of these conditions, or what explanation is offered for the fact that the number of traffic accidents, both property damage and personal injury, has increased steadily over the last four years, it is generally conceded that the curve is, in either direction, one of the most collision-prone in the county. According to Baker, the 1-94 and Jackson curve was one of the earliest interchanges on the interstate h i g h w a y , having previously been located on old US-12. It has also had a history of spectacular crashes. One of the most memorable of these carne less than a year after the official opening of the expressway's final link when, on Nov. 13, 1961, a Grayhound bus en route from Chicago to Detroit skidded off the rainslick roadway and tumbled down a 30-foot embankment while attempting to handle the curve. In that mishap, 27 persons were injured, but none died. Oddly enough, despite the rising accident total at the curve, fatalities there seem to be infrequent. From 1966 through 1968, no deaths were recorded, and last year there was but one. Nor has anyone been killed there yet in 1970. Sheriff Harvey came close, however. He and his 18-year-old son were eastbound on a borrowed motorcycle July 1 when linkage in the throttle apparently broke, causing the cycle to spurt out of control while rounding the sweeping curve. The cycle jumped the center median on 1-94 and landed in the opposite lanes of the freeway directly in the path of an approaching tractor - trailer truck. Immediately s werving to the right, the truck driver managed to avoid striking the Harvey's head-on, although the cycle did hit the truck's wheels, throwing the pair from the vehicle. A fractured left ankle and assorted lacerations were the extent of the injuries the sheriff suffered in his brush with death, while the younger Harvey also suffered severe lacerations. "We were lucky," Harvey later admitted, terming the área where his collision occurred "one heil of a curve." Another lucky motorist was cited by Ann Arbor pólice Lt. Robert Whitaker, who recalls an accident at the curve approximately eight years ago in which a sports car driver lost control of his auto at a high speed. "The guy was bounced right out of his car, landed on the median and skidded some 100 feet down it on the seat of his pants, says Whitaker. "By the time pólice had arrived on the scène, the guy was up, uninjured except for some scratches, and walking down the freeway after his car." While any vehicle is, of course, susceptible to going out of control on the curve under the proper conditions, large semi-trailer trucks have a particularly rough time of it, points out Sherman. He blames this primarily upon a relatively small bump in the pavement located just before the main grade in the curve' s right westbound lañe. "This bump is not discernible like a large rut would be," he explains. "All it amoünts to is a depression in the pavement and then a slight rise, which creates a sort of minitature ramp action. This, in turn, sets up oscillation in the empty -box trucks which pass over the bump and extends the trucks' suspension system." Sherman believes that the bump can, by initiating this "oscillation" in the empty trailer, cause the truck to go out of control when in the right combination with other factors, such as wet pavement or a driver behind the steering wheel u n f a m i 1 i a r with the! curve. "It's like taking off from a ski jump for unloaded trailer1 trucks," he claims, adding that passenger cars and loaded trucks don't feel the same effect when rolling over the bump. The answer to this problem? "A little physical repair needs to be done on the curve . . . to make a smoother bridge approach." An example of why Sherman is concerned with the plight of tractor-trailer rigs at the overpass was provided on July 14 when two such trucks went out of control there within moments of each other during an after-, noon rainstorm. In the second of these mishaps, two men inside the truck's cab were injured when the vehicle jack-knifed and ripped through a strip of guard rail. In the pólice report on the crashes, the curve was described as "unmarked" and "extremely dangerous." Since then, warning signs indicating the direction of the] curve have been placed there, and a 55 mile per hour speed limit has been posted. According to the Michigan Vehicle Code, 1968 revisión, the maximum speed for trucks weighing in excess of 5,000 lbs. is 60 miles per hour on interstate freeways. Too much speed and "overdriving" of the curve were the reasons offered by Baker in explanation of problems on the! 'overpass. "Most of the trouble there can be attributed to driver errors," he says. Still, henotesthatthe interchange was constructed in 1956 and possesses, under present standards, "a sub-tandard degree of curvature." Nowadays, Baker states, 2Vz degrees is the sharpest curve built into a freeway, while two degrees is normally favored. The curve around 194 at Jackson is, however, "a little over three degrees," he concedes. Nevertheless, Baker says there are no plans by the State Highway Department to rede-; sign the curve in the near I future. "We have nothing planned as far as correcting the geometrie banking there," he I conditions. In addition, 30 of the crashes list loss of control as the reason for the accident, and loss of control always happens much easier on slick pavement. The one fatal accident there in 1969 took place when a car spun out of control and off the road on the curve. Further, the study indicated that the months when the most collisions occur there are December, January and October; two of these months being traditionally snowy ones in Michigan. Strangely, however, February, always a sloppy, slushy month, had no accidents on the overpass last year. Both John Robbins, whose department compiled the above study, and Cpl. Hughes, who has policed numerous collisions on the curve over the past several years, agree that the overpass, when wet, is an unpleasant place for fast-moving motor vehicles. "When that road surface gets wet, cars are likely to skid out on it like ice," Robbins says. "It's a particularly bad curve for cars to gain traction on in winter." Hughes admits that a lot of smash-ups take place on the overpass, but refused to dismiss the curve as simply a dangerous one. "It needs some engineering as to the elevation jthere," he states, "because all the water drains off on one side." He also claims that this excess of water during rainy Iweather will cause some vehicles to "hydroplane" on the assms. "Geometrie banking," "substandard curvature" and all "oscillation" aside, one fact concerning the overpass which seems to stand out clearly is that the majority of its accidents occur when the pavement on the curve is wet or icy. A one-year study of collisions around the overpass, from Jan. 1 of 1969 to Jan. 1 of 1970, shows this dangerous-when-wet tendency. Compiled by the Ann Arbor Department of Parking and Traffic Engineering, the study records a total of 54 mishaps on or near the curve, withj 38 of these occuring on "slip-j pery," ' ' r ainy , ' : "icy,"J '"snowy" or "wet" pavement -1 curve, meaning that the tires are actually spinning on a thin layer of water atop of the pavement instead of the pavement itself. "This cause lost control," Hughes says, "and I do think the curve has a little more radius to it than many drivers might anticípate." He concurred with the opinión of Sherman that a bump in the road - "a raised concrete stretch where pavement slabs join" - will cause difficulty for empty trucks. According to a spokesman for the Michigan State Highway Department in Lansing, both the number of collisions and the number of injuries resulting from traffic mishaps at the overpass are increasing. A total of 20 accidents and 10 injuries were recorded by the state as having happened there in 1966, while those figures had grown to 50 accidents (in conflict with the city's study) and 39 injuries last year. And with the winter season approaching soon, it's a áafe bet that the 1-94 and Jackson curve will continue to plague motorists traveling it just as in the past. This map shows those streets in the city limits which receive rock salt treatment under the city's program of reducing the amount of salt to be used for deicing purposes. Those streets on the map covered in black are the only ones which would normally receive salt treatment in a winter storm. Side streets and neighborhood streets are treated with a sandchloride mixture, except for steep grades which also receive salt.