Wei Yan remembered that Ma Jun had added iron rings to the axles of the four-wheeled carriage in recent days, so that the iron and iron rubbed against each other, and grease lubrication was added in the middle to enhance the firmness of the wheels, reduce the friction of the car bearings, and make the carriage have a longer service life.

Wei Yan had a question: "Why was such a good road abandoned in this dynasty?" ”

Jia Xu said with a stunned face: "In the last years of the Qin Dynasty, the people's livelihood withered, and even the emperor did not have the ability to equip his imperial chariot with horses of the same color, and many generals could only ride ox carts. The gallop road on which there were no cars running, but it hindered traffic, so some of the gallop roads that Qin Shi Huang worked hard to build were destroyed in the war, and most of the rest were also demolished after the war and became ordinary highways. The national strength of our Han Dynasty only recovered after a long time, and the long-term implementation of Huang Lao's learning and inaction rule, so there has been no labor and mobilization to rebuild the Chi Road, plus the Qin Dynasty's Chi Road is too wide, and later many roads were reclaimed for arable land, narrowed, or even completely ceased to exist.

Also, the Qin Dynasty Chidao was used for long-distance transportation, and our Han Dynasty had been divided into princes for a long time, and the people everywhere had no need for long-distance transportation, and the transportation line became shorter, so it lost the need to build Chidao. ”

Speaking of this, Jia Xu looked solemn: "My lord, my subordinates believe that you don't want the Liu Han royal family to engage in any more feudal systems, and you have the ambition to expand the borders, whether it is military or civilian, Chidao can come in handy." My lord, don't say anything about it, your determination to rebuild the gallop has been decided. ”

Wei Yan smiled and patted Jia Xu's shoulder: "Cultivation will definitely be cultivated, but we have a lot of places where we spend money now, and the people have just stabilized. ”

Jia Xu smiled and said: "Lord, we don't need to repair all of Qin Chi Dao, we only need to build a new one and rebuild one."

The Chi Road built in the Qin Dynasty mainly includes the Oriental Avenue of Xianyang out of Hanguguan along the Yellow River through Shandong Dingtao and Linzi to Chengshanjiao, the Northwest Avenue from Xianyang to Lintao in Gansu, the Qinchu Avenue from Xianyang to Jiangling in Hubei Province through Wuguan in Shaanxi Province and Nanyang in Henan Province, the Sichuan-Shaanxi Avenue from Xianyang to Bashu, in addition to the Jiangnan New Road in the south and Shuguang in the south, and the Jiangnan New Road in the southwest to Guilin, Guangxi, and the Northern Avenue from Jiuyuan to Jieshi in Hebei along the Great Wall in the east. We don't need to build a new road to the Loop, we only need to build a road from Yiyang to the Northern Avenue, from this north-south road to the North Avenue, and then turn to the North Avenue to reach the place where the North Avenue and the straight road meet, and then we can cross the north and south of the Loop. ”

Wei Yan asked Jia Xu to take out a large map north of the Yellow River, pointed to the route Jia Xu said with his hand, and couldn't help shaking his head and said: "This gallop road does have to be built, but if you follow this gallop road to the Hetao, it will be a big circle, it is better to build another one across Taihang, Luliang, straight to the Hetao, this gallop road through Shangdang County Zhihuguan, Hedong County Beiqucheng, Shangjun Diaoyin City, Beidi County Qingyang City, Anding County Linjing City, with this gallop, you can remotely control Shangdang County, Hedong County, Shangjun, Beidi County, Anding County, but not afraid of Ma Teng, Han Sui peeked into the rich Hetao. ”

Jia Xu frowned, and said with a wry smile: "Lord, this gallop road not only has to cross the mountains of Taihang and Luliang, but also cross the Yellow River, and there are countless hills and rivers in the middle. ”

Wei Yan sighed in disappointment, after all, this is the end of the Eastern Han Dynasty, unlike later generations, some leaders in later generations patted their heads, and the moat must change the way, Wei Yan is no matter how good he wants to be happy, he must also comply with the technical conditions of this era, and he can't force it.

Looking at the lord's disappointed face, Jia Xu hurriedly smiled and said: "Lord, although we can't build a complete gallop road, we can build it in sections, and we can detour where we can't get over, anyway, the horses also need to rest, and the horses must be changed in the middle, and the gallop road doesn't need to be so complete." ”

Jia Xu lived in Beidi County all the year round and was very familiar with the terrain north of the Yellow River, so he roughly marked on the large map those places that could be slightly leveled to build a gallop road, where the place had to be detoured, so that the route drawn was very similar to the strands of later generations.

Jia Xu said with a smile: "Lord, don't look at these routes are fragmented and twisted, but between each section, the carriage can travel quickly, even faster than the general cavalry marching speed, after the completion of the construction of these sections of galloping roads, from Yiyang to Beidi County, it can be reached in twenty days, and before that, it takes at least two months, which is enough to save forty days." ”

For the army, time is victory, and it can change the outcome of a battle in a few days, let alone forty days, Wei Yan happily ordered to rebuild the Qin Straight Road and rebuild the Northern Chi Road.

Jia Xu pointed to the straight road and said very excitedly: "Lord, it's unbelievable to say it. This Qin straight road began in the 35th year of Qin Shi Huang, to the 37th year of September before, is along the mountains and desert grassland to build a long 1,800 miles, about 18 zhang wide carriage and horse avenue, only two and a half years, to complete the line selection, reroute, construction, construction of post stations and other tasks. ”

Wei Yan understood what Jia Xu meant, and wanted him to follow Qin Shi Huang's example, recruit people's husbands, and repair the straight road and gallop road as soon as possible.

Wei Yan shook his head and sighed: "Emperor Qin is so happy, he wants to blame everything, and he spares no effort from the people, so he can naturally make something in the shortest possible time." And if we want the Han Dynasty to prosper, and we don't want the Han Dynasty to die in our hands, then we must be considerate of the people's power and not levy it on a large scale. These roads are to cross mountains and rivers, the project is huge, the task is arduous, it is impossible to complete in a year and a half, three years barely show the prototype, with a period of five years.

Wenhe, you said that you can build in sections, then we will build together from the starting point and the end point, and use a section after repairing, and use it while repairing. ”

After Wei Yan and Jia Xu made a five-year plan to build a straight road and a galloping road, Jia Xu reminded: "My lord, if you want the Chidao to play a role, you must issue a decree and strictly enforce the same track. ”

"Cars on the same track?" Before that, Wei Yan could understand Qin Shi Huang's book and text, unified currency, and unified weights and measures, but he did not understand the "car on the same track".

Later generations of Guo Moruo once said that the car on the same track is to unify the social system and customs, but now it seems that it is absolutely far-fetched. In addition, some people interpret "car on the same track" to mean that the distance between the wheels must be the same, which is literal, but also difficult to explain.

Wei Yan thought to himself, on the modern highways of later generations, the wheel spacing of various types of cars was different, and there was nothing wrong with it, so why did the Qin Dynasty have to use the same wheel spacing? Moreover, Qin Shi Huang's own chariot was pulled by six horses, which is obviously not the same as the wheel spacing of ordinary one- or two-horse horses.

Wei Yan is now standing on Qin Chi Road, and all the original doubts about "cars on the same track" have disappeared.

In the Warring States Period, the other six countries also built similar roads for their own transportation convenience, just like the later Republic of China period, all the warlords also built their own railways, all according to their own needs to determine the width of the railway, so that the trains in other places can not drive to their own territory, after the liberation, the country is highly unified, all these unreasonable phenomena will be eliminated, the national unified use of the international standard railway gauge, 1435mm.

After Qin Shi Huang unified China, the same track of the carriage is the distance between the two tracks of the unified gallop road, so as to determine the distance between the wheels of the carriage, the distance between the two axles of each car is equal, and the carriage of the whole world can be driven to any gallop road, which is convenient for transportation.

Wei Yan dictated, Jia Xu supplemented and wrote a handwritten request, to the Xudu court to rebuild the Qin Straight Road, Qin Chi Road and the law of re-driving on the same track, and the great significance of rebuilding the straight road to the military and the people was briefly and concisely expounded.

Writing to the Xudu Imperial Court is just a procedure, no matter whether Cao Cao agrees or not, Wei Yan is ready to do that!

Jia Xu pointed to the junction between Beidi County and Shangjun on the map: "Lord, you can't take it here, you can't keep it." ”

Wei Yan asked, "Wenhe, is this a key thing?" ”

Jia Xu said with a smile: "My lord, this place is called Hengling, and the straight road comes here through the Hetao grassland, and through Hengling from north to south, until Ganquan Mountain at the southern end of Hengling. Hengling is a huge mountain range, the mountainous area is vast, there are many branch ridges, the terrain is complex, the terrain is dangerous, it is the barrier of Yanzhou, Gyeongju and Guanzhong, it controls the river valley avenue on the east and west sides, and it is the place where soldiers must fight.

The river valley avenues on both sides of Hengling, one is the Yanchuan Road leading to Yanzhou in Chang'an, and the other is the Malian Road that leads directly to the pass under Helan Mountain, the river valley area is rich in water and grass, and the Hu people are used to coming and going to the river valley avenue, so they have become the main passage for the Hu people to go south. The Yanchuan River valley is relatively narrow, and it is more difficult for the Hu people to go south, so they often go south from the Malian River Road. From the Malian River to the south, not only from the Guanzhong distance is closer, but also mostly dirt hills and hills, the danger is not big, easy to attack. In addition, there is a road, in the west of the Malian River, Xiaoguan Road under Liupan Mountain, this road is relatively flat, the water and grass are also more abundant, which is more conducive to cavalry activities, the disadvantage is that it is far away from Guanzhong, but in the case of Yanchuan Road and Malian River Road are blocked, the Hu people often go south from this road. Malian River Road, Xiaoguan Road, and Yanchuan Road are all related to the safety of Guanzhong.

Yanchuan Road, Malian River Road, Xiaoguan Road, these three river valley passages, Malian River Road is in the middle, there are some roads between the three river valley roads can be connected to each other, in this way, Malian River Road is also under the attack and pressure from Yanchuan Road and Xiaoguan Road, so the position of Malian River is more prominent, Yanchuan Road and Malian River are located on the east and west sides of Hengling, and the straight road is above Hengling, in this way, the straight road plays a role in controlling the river valley avenue on both sides.

In the third year of Emperor Wen of the former Han Dynasty, King Youxian of the Xiongnu entered Henan, attacked Shangjun, and failed to continue south along the Yanchuan Road, because of the control of the straight road. At the same time, Emperor Wen sent the general Guan Ying to lead the army to march from the straight road to resist the Xiongnu, and the Xiongnu quickly withdrew from the Hetao to ensure the safety of Guanzhong.

In the fourteenth year of Emperor Wen, the old Shangdan of the Xiongnu tribe led 140,000 cavalry to invade Chaona and Xiaoguan, killed the commander of the northern land, plundered a large amount of wealth, and then attacked Pengyang, and its vanguard reached Yonghe Ganquan. The Xiongnu came fiercely this time, why did Lao Shangdan retreat to Saiwai after staying in the Sai for a month, why didn't he take the Malian River Road, which is closer to Guanzhong, and the Xiaoguan Road, which is far away from Guanzhong? It is because the straight road regulates the Malian River channel.

The control effect of the straight road is also manifested in the control of the traffic around Hengling, the Yanchuan Road and the Malian River on the east and west sides of the Hengling are two parallel river valley roads, and the connection between them must pass through the Hengling to be connected, complement each other and influence each other, so there are many checkpoints in the Hengling that are on the straight road, such as Fuyuan Pass, Diaoling Pass, Wutingzi, Lao Yeling and other places are the main intersections, controlling the traffic around the Meridian Ridge, becoming an important throat to control the Yanchuan Road and the Malian River Road, and becoming a natural barrier for the border county town and Guanzhong.

After the fall of the Qin Dynasty, the straight road still played an important role. In the early years of the Han Dynasty, the Huns tried to invade Guanzhong twice, one of which entered Xiaoguan and reached Yongxian and Ganquan. Since the Huns intended to watch Ganquan, why didn't they go south directly from Jiuyuan, but they had to make a detour to the foot of Liupan Mountain? In the east and west of Hengling, they are the Luo River Valley and the Malian River Valley. The Hu people invaded the Central Plains in the south, usually through river valleys. And at that time, the Luo River Valley and the Malian River Valley were not harassed, what is the reason for this? Extrapolating the actual situation, it was the addition of a straight road on the Hengling that made the Huns have to worry about it. Although they temporarily controlled the Hetao, they did not dare to entrench it for a long time. At that time, King Zuoxian of the Xiongnu once occupied the Yinshan and Hetao areas, but soon withdrew again, which is the reason. ”

When Wei Yan heard Jia Xu say this, he attached great importance to the defense of the straight road, so he sent an order to Xu Huang, who stayed in the Hetao, and asked him to quickly send men and horses to occupy the Hengling area.

Jia Xu stared at the Hengling on the map and sighed: "In the former Han Dynasty, in the first year of Yuan Feng, Emperor Wu went from Mount Tai to the east to the sea, to Jieshi, from Jiuyuan in the north of the Liaoxi calendar, to Ganquan, and he took the straight road. Fortunately, Sima Qian had accompanied him on this tour, so he was able to clearly record the starting and ending places of the straight road, and also said that Xingguan Mengtian built the Great Wall pavilion barrier, the trench mountains and valleys, and the straight road, and the strength of the people, and summarized the pros and cons of the Qin people in opening up the straight road.

The former Han Dynasty not only actively used the straight road built in the Qin period to defend against the southern invasion of the Xiongnu, but also made efforts to maintain the straight road, adding Zhilu County and Jiedao County in Beidi County, which were located at the north and south ends of the straight road in the Meridian Ridge section, and strengthened the control of the straight road. On the other hand, in today's dynasty, passive defense, inaction, good straightness, and degraded to Si, which makes people sigh. ”