When using app.use in handler request parmeter don't define route (req.route === undefined)

[Anrei Dergaev]

Express 4.4.1

router.routers.root.use('/route/:id?', function (req, res) {
console.log(typeof req.route); //in log 'undefined'
res.send('GET');
});

router.routers.root.all('/route/:id?', function (req, res) {
console.log(req.route instanceof Route); //in log 'true'
res.send('GET');
});

Why?