One-way restrictions on local streets, which tend to have low traffic stress, can create a significant barrier to low-stress cycling. Contraflow, a treatment that undoes one-way restrictions on bike travel, has the potential to improve low-stress connectivity. Although contraflow is applied routinely in the Netherlands and Belgium, it has been sparingly applied in the United States. We propose refined measures of connectivity and accessibility that account for one-way restrictions by requiring a low-stress round trip path between origins and destinations. Different methods of associating origin–destination demand from polygons with a street network were analyzed. These methods are particularly important where there are one-way restrictions and irregular street networks because of the assumptions they entail in relation to first- and last-segment travel. In a case study of Greater Boston, we found that with the current bike network, low-stress connectivity between homes and jobs would increase from 1.2% to 8.7% if one-way restrictions on local streets were eliminated. We also found that even with a dense mesh of low-stress main bike routes, connectivity would still be 16% lower without contraflow on local streets than with. These results suggest that creating a network of main bike routes is not always enough; it is also important to provide contraflow on local streets. The Boston study also found that providing contraflow on selected links representing only 3% of local one-way street mileage delivered 40% of the connectivity impact of universal contraflow. Based on this finding, a method is proposed for prioritizing streets for contraflow conversion.

当地街道的单向限制往往具有较低的交通压力，可能会对低压力骑行造成重大障碍。Contraflow 是一种解除自行车旅行单向限制的处理方法，有可能改善低压力连接。尽管在荷兰和比利时经常使用逆流，但在美国却很少使用。我们通过要求起点和终点之间的低压力往返路径来提出改进的连通性和可访问性措施，以解决单向限制。分析了将多边形的起点-终点需求与街道网络相关联的不同方法。这些方法在存在单向限制和不规则街道网络的情况下尤其重要，因为它们需要与第一段和最后一段旅行相关的假设。在大波士顿地区的一项案例研究中，我们发现，如果取消对当地街道的单向限制，使用当前的自行车网络，家庭和工作之间的低压力连通性将从 1.2% 增加到 8.7%。我们还发现，即使有密集的低压力主要自行车路线，在当地街道上没有逆流的情况下，连通性仍会比没有逆流的情况低 16%。这些结果表明，创建主要自行车路线网络并不总是足够的；在当地街道上提供逆流也很重要。波士顿的研究还发现，在仅占当地单向街道里程 3% 的选定链路上提供反向流量可实现通用反向流量的 40% 的连通性影响。基于这一发现，提出了一种对街道进行优先排序以进行逆流转换的方法。