【英语中国】中国大规模塞车症结未解

Congestion has eased on a main route into Beijing after a traffic jam held up travelers for more than 10 days. But factors that contributed to the tie-up remain and similar problems could occur any time, according to the Texas Transportation Institute. Similar jams could also happen in the U.S. on a smaller scale.

The College Station, Texas, research group that studies traffic trends around the world, says what happened in China reflects patterns in traffic flow that exist in the U.S. and wherever highways are used at a rate near full capacity. The worst traffic snarls in the U.S are typically measured in hours, not days. But like the Chinese jam they tend to occur quickly as roads are pushed beyond capacity.

The rule of thumb for traffic capacity on major U.S. highways is 2,000 cars per hour in each lane, but that number could be lower in China where roads tend to have narrower lanes and shoulders, says Shawn Turner, a senior research engineer with the Texas group.

The traffic jam near Beijing resulted from a combination of peak seasonal travel, increased freight traffic and road construction. But it was made worse by a lack of information about traffic conditions available to some motorists. As the traffic jam grew many people continued to drive into it, probably not knowing what they were in for. That's because while traffic reports in China's cities are thorough, they aren't as good or easy to get in outlying areas, says Turner, who has advised Chinese transport agencies on improving traffic management.

Another critical difference between China and the U.S is the maturity of our highway systems. While China's relatively young highway system resembles the U.S Interstate network, the country lacks the smaller state and county roads that offer U.S drivers alternative routes when they are slowed by traffic congestion. Taking the back roads just isn't an option in many cases.

'There isn't the redundancy we take for granted here,' says Turner, adding that statistics indicate the traffic situation around Beijing is still getting worse. It could take years to get traffic under control as about 1,900 vehicles are added to Beijing's street each day according to Texas Transportation Institute estimates.

入北京的一条主干道上的交通堵塞已使旅客受困10多天，目前道路拥堵情况终于有所缓解。但据德克萨斯运输研究所（Texas Transportation Institute）称，导致堵塞的因素依然存在，而且类似的问题可能随时再次发生。相似的交通堵塞问题也可能发生在美国，不过堵塞规模较小。

研究全球交通趋势的这家研究机构表示，中国发生的情况反映了在美国及任何地方当公路接近饱和时的交通流量状况。但美国发生的最糟糕交通堵塞通常只是几小时，而不是几天。像这次交通堵塞一样，中国的交通拥堵经常很快发生，因为公路运力已超饱和。

德克萨斯运输研究所高级研究工程师特纳（Shawn Turner）说，美国主要公路的交通运力凭经验是每车道每小时通行2,000辆汽车，但在中国这一数据可能较稍低，因为中国公路的车道和路肩通常较窄。

特纳说，北京附近的交通堵塞是季节旅游高峰、货运增加及道路修建等综合因素造成。但一些车主因为缺少交通状况的信息，而使问题更加严重。随着交通更加堵塞，许多人还在驾车驶入公路，可能不知道他们将遭什么罪。这是因为尽管中国城市里交通信息充足，但边远地区就得不到这么好或这么容易得到交通信息了。特纳就改善交通管理向中国相关运输机构提供咨询服务。

中美另一个关键差异是公路系统的成熟度。尽管中国年头相对较少的公路系统与美国州际交通网络相似，但中国缺少较小的省道和县级公路，这样的道路使美国车主在遭遇道路堵塞时可以有其他路线的选择。在许多情况下，似乎无法原路返回。

特纳说，中国不存在我们美国人习以为常的道路冗余度，他补充说，统计数据显示，北京周边的交通状况仍在恶化。德克萨斯运输研究所估算，北京每天新增约1,900辆汽车，可能要花费数年时间才能使交通状况得到有效控制。