Somehow, this test suite has changed and now I cannot pass Test 62, even though I did not use a lookup table solution. Please advise.

The solution is timing out (it is just taking too long). I would recommend to change your code to use a single call to dijkstra_lanes instead of one separate call for each StartLane-to-EndLane combination. You may do so, for example, by adding two nodes to your graph, one "start" node that is connected (with distance 0) to every non-blocked lane in the first row, and one "end" node that is connected (with distance 0) to every non-blocked lane in the last row. Then you will only need to call dijkstra_lane once to compute the optimal path distance of this extended graph, instead of calling your function N1*N2 times (for each of the N1/N2 first/last -row non-blocked positions)

Thank you for the recommendation.