因为在市中心，常常堵车，所以打车很不方便。

Yīnwèi zài shìzhōngxīn, chángcháng dǔchē, suǒyǐ dǎchē hěn bù fāngbiàn.

Because in the center of the city, there's often traffic, so calling a cab isn't convenient.

不好意思，我想我会迟到，因为路上遇到堵车。

Bù hǎoyìsi, wǒ xiǎng wǒ huì chídào, yīnwèi lùshang yùdào dǔchē.

I'm sorry, I think I might be late because I'm in a traffic jam.

前面可能发生了交通意外，所以这里堵车堵得很厉害。

Qiánmiàn kěnéng fāshēng le jiāotōng yìwài, suǒyǐ zhèlǐ dǔchē dǔ de hěn lìhai.

There might be an accident up ahead, so the traffic jam here is quite serious.