随着美国铁路公司（Amtrak）关键的波士顿至华盛顿东北走廊（Boston-to-DC-Northeast）的服务今天恢复正常，上周费城发生的188次列车暴力脱轨事件仍存在疑问，造成数人死亡，数十人受伤。据报道，三位数的速度接近一个限速仅为50的弯道，这似乎是造成事故的原因——但某种物体显然撞上了沿途的另一列火车，国家运输安全委员会“不排除”物体也撞上188的可能性。

尽管如此，速度仍然是调查的中心焦点，调查的重点转向了PTC-积极列车控制，这是铁路行业的一项成熟技术，使用信号系统、计算机、，以及全球定位系统，以防止列车速度过快，并与其他列车相撞的情况下，工程师是不能胜任或犯了错误。PTC作为改善铁路安全的一种工具非常有希望，因此联邦**已下令在2015年底前在美国铁路网的广大地区部署PTC。此外，这起事故还导致联邦铁路管理局要求美铁“立即”对发生灾难的轨道区段启用自动控制。

但美国铁路公司（Amtrak）前首席执行官大卫休斯（David Hughes）辩称，该公司在部署PTC方面并没有拖后腿——事实上，它正在“尽可能快地行动”，他在一封致《边缘》（the Verge）的电子邮件中说：

In fact, both Amtrak and the freight railroads have been going full speed in implementing PTC, but there are some formidable challenges. For the freight railroads, when PTC technology was mandated by Congress, the technology to implement it did not exist. So, railroads and the supply industry had to effectively invent it. Everyone agreed that it could be invented, but that takes time and lots of integrity and safety testing. In addition, the system required radio spectrum that wasn't available. So the railroads had to go out and buy up in bits and pieces the radio spectrum to implement PTC. Moreover, even with spectrum, sites for new radio towers were required which had long permitting process. Every tower had to be approved by the local Indian tribe to ensure it wasn't near some sacred site. Permitting was a real mess. No doubt the railroads felt that PTC did not have enough benefits to justify the $10 [billion] or so in costs, but I believe, as an insider in the railroad industry, that they have moved with all due haste in implementing PTC. As for Amtrak, the equipment for PTC was already installed in the track at the time of the accident. It had not been made operational because Amtrak had only recently received FCC approval for their use of the spectrum they purchased. So, the timing was really unfortunate, but Amtrak was moving as fast as it could to implement PTC on that curve.

休斯说得没错，联邦通信委员会最近刚刚签署了美国铁路公司在该地区的PTC频谱：联邦通信委员会的罗杰·谢尔曼（Roger Sherman）在博客中证实，批准是在今年3月，同时还指出，铁路公司必须通过拍卖或从现有许可证持有人处“依法”获得频谱——基本上，FCC不能凭空推出新的光谱来满足PTC的要求。不过，这并不是说，美国铁路公司（Amtrak）早先提出的审批请求不一定能让PTC更快地部署到这条曲线上；谢尔曼说，联邦通信委员会在3月份“美铁提交最终修正案两天后”就批准了美铁的请求。

该机构称，美国国家运输安全委员会（NTSB）可能还要“长达12个月”才能发布有关坠机根本原因的最终报告。下一次调查的最新情况预计将在本周晚些时候公布。