BEWARE OF TRAM LINES
From the 1934 Wills Cigarettes 'Safety First' album.
"Beware of tram lines for they are most treacherous, especially when wet. Avoid crossing them at points or sharp corners, where the worn edges of the rail often present knife-like edges to your tyres. To obviate the risk of catching your tyre in the groove of the rail, cross the lines at as nearly right angles as possible, after giving the appropriate signal to warn the following traffic of your intention (see illustration). As wet tramlines are the most 'skid-provoking' of surfaces, special care is required in wet weather, when it is desirable to reduce speed and free-wheel over the rails."