sides of the right-of-way between Ridgeland and Central Avenues to “channelize” people
to the crossing point at Austin. Tr. 1256-57. Dr. Berg also posited that it might eventually
be necessary to build a new crossing at the site of the accident itself. Tr. 1255. He did not
consider the cost of such a crossing, however.
With regard to the crossing at Austin, Dr. Berg admitted that an overpass would
be “much more effective” than an at-grade crossing. Tr. 1262. According to Dr. Berg, the
key to preventing trespassers from jumping onto trains was to erect a “physical barrier”
that would prevent people from walking “right up to . . . the train.”8 Tr. 1315. At an at-
grade crossing, though, there would “absolutely” have to be an “opening in the fence,” so
trespassers could “physically come in contact with a train” and have the “opportunity to
jump on the side of a moving train if they cared to.” Tr. 1345-46, 1348-49.
Although Dr. Berg thus admitted in substance that an overpass would be
necessary to keep trespassing children from having access to the tracks, and hence
moving trains, he had never before been involved in the design or construction of one. Tr.
1321, 1325. He did not prepare a “detailed design or cost estimate” of the overpass he
advocated; in fact, he could not even provide any sketches of it. Tr. 1323, 1360. He had
not settled on the most basic of design parameters, such as the clearance over the tracks
(Tr. 1324, 1361), the width of the overpass (Tr. 1323), and how the approaches to the
overpass would function (Tr. 1254, 1359-60). Dr. Berg also brushed aside other planning
8 An at-grade crossing would still have given Choate an “opportunity . . . to get on the side of a train at an open place in the fence” where the crossing was, and therefore would have been ineffective in preventing the accident. Tr. 2089; see also D. Choate Dep. 120 (A27) (agreeing that at-grade crossing would not have prevented him from gaining access to moving trains). Because the crossings at Ridgeland and Central were also “at-grade” (Tr. 1349, 1886, 2441), it is inexplicable that Dr. Berg did not consider the cost of converting them to overpasses as well.