根据CAA（Canadian Automobile Association）最新发布的一个报告，全加拿大最堵的20个路段中，多伦多占了整整一半；其中央街与427高速之间的401、Don Mills Road与 Finch Avenue之间的DVP/404高居这个榜单的第一和第二位。
CAA将这些最堵的路段称为瓶颈路段（bottlenecks），并表示这个结果是通过分析各省市总共3,000公里的GPS资料获得。
如果考虑因堵车而耽误的时间，401通过多伦多市中心的一段，即央街与427高速之间的路段在美国和加拿大各城市中排名第九，排名第一的是芝加哥Roosevelt Road 与 N Nagle Avenue之间的I90；第二到第七全部在洛杉矶境内；第八和第十则在纽约。换言之，央街与427之间的401是唯一进入这个榜单前十名的加拿大瓶颈路段。
加拿大瓶颈路段第二多的城市是蒙特利尔，有三个路段列入最堵路段前十名，另外有两个列入最堵路段前二十名。
排在蒙特利尔之后的城市是温哥华，也有两个路段列入前十，两个列入最堵路段前二十。
除了这三大城市之外，魁北克城也有一个路段列入最堵路段前二十。
报告作者 Vijay Gill指出，严重的道路堵塞不仅有经济成本，也有环境代价。巨大的车流量造成了严重的交通瓶颈，尤其上下班高峰时间不堪重负，堵塞严重，并大大增加了通勤时间。
该报告估计，在多伦多最繁忙的路段，一名司机因堵车每天平均要浪费36分钟甚至60分钟，一年下来司机们在这个路段因堵车浪费的时间总共可达到320万小时。如果计算几条加拿大堵塞最严重的瓶颈路段，那么一年因堵车浪费的时间就是1150万小时，消耗的汽油可达2200万升。
加拿大最堵的20个瓶颈路段
1. Toronto, Highway 401 between Highway 427 and Yonge Street
2. Toronto, Don Valley Parkway/Highway 404 between Don Mills Road and Finch Avenue
3. Montreal, Highway 40 between Boulevard Pie-IX and Highway 520
4. Toronto, Gardiner Expressway between South Kingsway and Bay Street
5. Montreal, Highway 15 between Highway 40 and Chemin de la Cote-Saint-Luc
6. Toronto, Highway 401 between Bayview Avenue and Don Mills Road
7. Toronto, Highway 409 between Highway 401 and Kipling Avenue
8. Montreal, Highway 25 between Avenue Souligny and Rue Beaubien
9. Vancouver, Granville Street at SW Marine Drive
10. Vancouver, W Georgia Street between Seymour Street and W Pender Street
11. Toronto, Highway 401 between Don Valley Parkway and Victoria Park Avenue
12. Toronto, Black Creek Drive between Weston Road and Trethewey Drive
13. Toronto, Highway 401 between Mavis Road and McLaughlin Road
14. Montreal, Highway 40 between Highway 520 and Boulevard Cavendish
15. Vancouver, Granville Street between W Broadway Street and W 16th Avenue
16. Montreal, Highway 20 near 1re Avenue
17. Quebec City, Highway 73 between Chemin des Quatre Bourgeois and exit to Avenue Dalquier
18. Toronto, Highway 401 interchange at Highway 427
19. Toronto, Highway 400 at Highway 401
20. Vancouver, George Massey Tunnel on Highway 99
美国加拿大因堵车而耽误时间最长的10个路段：
1. Chicago, I90 between Roosevelt Road and N Nagle Avenue
2. Los Angeles, I405 between SR22 and I605
3. Los Angeles, I10 between Santa Fe Avenue and Crenshaw Boulevard
4. Los Angeles, I405 between Venice Boulevard and Wilshire Boulevard
5. Los Angeles, US101 between Franklin Avenue and Glendale Boulevard
6. Los Angeles, I110 between Exposition Boulevard and Stadium Way
7. Los Angeles, US101 between Sepulveda Boulevard and Laurel Canyon Boulevard
8. New York and Union City, Lincoln Tunnel between 10th Avenue and John F. Kennedy Boulevard
9. Toronto, Highway 401 between Highway 427 and Yonge Street
10. New York, I95 between I895 and Broadway