A method for controlling a vehicle in a degraded visual environment , comprising: identifying a degraded visual environment corresponding to a phase of a route followed by the vehicle ; determining , based on the phase of the route, a first segment of a trajectory of the vehicle along which to search for a location with an improved navigation environment ; causing the vehicle to follow the first segment until: (i) identifying the improved navigation environment , or (ii) reaching an end of the first segment without identifying the improved navigation environment ; determining a second segment of the trajectory based on whether the improved navigation environment has been identified; and causing the vehicle to follow the second segment ; wherein: identifying the degraded visual environment comprises: receiving sensor data obtained by one or more sensors on the vehicle ; determining a difference between the sensor data and expected data; and identifying the degraded visual environment based on determining the difference between the sensor data and the expected data; and the one or more sensors comprise a Light Detection and Ranging (LIDAR) device , and determining the difference between the sensor data and the expected data comprises determining a difference between a number of returning light pulses represented by the sensor data and an expected number of returning light pulses. identifying a degraded visual environment corresponding to a phase of a route followed by the vehicle ; determining , based on the phase of the route, a first segment of a trajectory of the vehicle along which to search for a location with an improved navigation environment ; causing the vehicle to follow the first segment until: (i) identifying the improved navigation environment , or (ii) reaching an end of the first segment without identifying the improved navigation environment ; (i) identifying the improved navigation environment , or (ii) reaching an end of the first segment without identifying the improved navigation environment ; determining a second segment of the trajectory based on whether the improved navigation environment has been identified; and causing the vehicle to follow the second segment ; wherein: identifying the degraded visual environment comprises: receiving sensor data obtained by one or more sensors on the vehicle ; determining a difference between the sensor data and expected data; and identifying the degraded visual environment based on determining the difference between the sensor data and the expected data; and the one or more sensors comprise a Light Detection and Ranging (LIDAR) device , and determining the difference between the sensor data and the expected data comprises determining a difference between a number of returning light pulses represented by the sensor data and an expected number of returning light pulses. identifying the degraded visual environment comprises: receiving sensor data obtained by one or more sensors on the vehicle ; determining a difference between the sensor data and expected data; and identifying the degraded visual environment based on determining the difference between the sensor data and the expected data; and receiving sensor data obtained by one or more sensors on the vehicle ; determining a difference between the sensor data and expected data; and identifying the degraded visual environment based on determining the difference between the sensor data and the expected data; and the one or more sensors comprise a Light Detection and Ranging (LIDAR) device , and determining the difference between the sensor data and the expected data comprises determining a difference between a number of returning light pulses represented by the sensor data and an expected number of returning light pulses. <EOS>