M40 reopened :-(

As I was taking the reading the motorway was reopened. With the first vehicles the sound goes I into the high 50's.

43db Car on fire, motorway closed this morning?

The Google traffic map shows no vehicles on our section of the motorway.

Cloudy, windy, warm

Clear sky, no wind, 19°C

Low reading at front door,  higher reading on back decking.

Recording details

 I am taking the readings from my back decking at about 1.5m off the ground unless otherwise stated.  The location of the reading is indicated by the yellow arrow on the map.

First reading with new app

This is the first reading with the new app.
Sunny day, low wind.